Researchers have determined supplementing horses’ diets with protein within a short but safe timeframe after exercise might help them build muscle mass more than providing the same supplement at regular mealtimes.

A high-protein snack—given as soon as the horse is resting again—could add critical amino acids to the bloodstream when muscles need them for repair and damage control, said Patty Graham-Thiers, PhD, professor and department head of the equine studies program at Emory & Henry University, in Virginia.

In a previous study Graham-Thiers and her colleagues found that supplementing young and even senior horses’ diets with amino acids helped improved their muscle mass—which horses naturally lose with advancing age. It made her wonder whether the supplements might be even more useful if they’re provided right when the body needs them most, shortly after exercise.

“In humans it’s common to consume protein post-exercise to help with muscle mass recovery and development, especially in body builders,” she said. “So, I thought, what if amino acids are delivered (to horses) after exercise when the body is recovering and needs amino acids, either for repair or development of muscle tissue?”

Feeding Horses a High-Protein Supplement After Exercise

To find out, Graham-Thiers and Kristen Bowen, BA, an equine exercise and nutrition research assistant at Emory & Henry, tested the effects of supplementation timing on eight healthy adult riding school horses. The horses participated in light to moderate maintenance exercise one to two hours per day, five days per week for 12 weeks.

Caregivers provided all the horses morning and evening meals consisting of grass hay, textured feed, and corn. In addition, the animals consumed a daily high-protein pellet made of 32% crude protein.

Half the horses received the protein supplement split into their two daily meals, while the other half received the supplement about 20 minutes after exercise—once their heart rates, breathing, and body temperatures dropped to regular resting levels. On rest days without exercise, these four horses ate their protein pellets as a separate midday snack.

The team collected urine and feces from each horse for four days before and after the 12-week experiment. They also took blood samples at the start and end of the study period, which they drew immediately after exercise and one and three hours later.

Studying the Effects of Feeding Timing on Muscle Health

The researchers used the urine and fecal samples to calculate nitrogen balance. Blood plasma samples allowed them to measure amino acid concentrations, albumin, plasma urea N (PUN), creatine kinase (CK), and creatinine.

The results of these tests revealed horses receiving supplementation in their meals had higher plasma concentrations of amino acids than those receiving the supplement shortly after exercise. The researchers explained this is likely because the horses had consumed more protein before exercise than the others, which had not yet had their daily protein pellets.  

The horses receiving the supplement after exercise had rising amino acid concentrations at the one-hour and three-hour post-exercise readings—likely reflecting a beneficial amino acid pool, the team said. The other horses’ amino acid concentrations, meanwhile, dropped.

Additionally, horses receiving the supplement just after exercise retained nitrogen better, which suggests they might have a timelier supply of proteins and amino acids for muscle protein repair and development.

The post-exercise supplementation group also had higher creatinine levels (a known marker of muscle mass) in their plasma. And they had less creatine kinase—an indicator of muscle protein damage or breakdown. This suggests horses might have been recovering faster after exercise than the other group, the researchers said.

Combined, the findings suggest feeding horses a high-protein meal shortly after exercise could help boost levels of circulating amino acids, which could aid muscle protein development while protecting against muscle protein breakdown.Even so, Graham-Thiers said more research is necessary before she and her colleagues can offer concrete supplementation guidelines.

Take-Home Message

“Ideally, I would suggest providing a small high-protein meal when it is safe to do so after exercise,” she noted. “However, this is not always practical. I would encourage riders to be aware of the time frame between feeding and exercise; the longer that time has been, the more important it might be for recovery to offer a small high-protein meal after exercise.”

The study, ”Timing of feeding a protein supplement on nitrogen balance and plasma amino acids during exercise recovery in horses,” appeared in the Journal of Animal Physiology and Animal Nutrition in July 2024.

With hurricane season upon us, horse owners must take proactive measures to ensure the safety and well-being of their animals. Here are some tips from the Louisiana State Animal Response Team (LSART), the Louisiana Department of Agriculture and Forestry, and the LSU School of Veterinary Medicine for horse owners to effectively prepare in areas prone to hurricane damage: 

Family Preparedness

Develop a personal plan with provisions for your entire family, including your animals, and update the plan yearly. Saving the Whole Family is a useful guide from the American Veterinary Medical Association (AVMA). 

Health and Identification

• Ensure your horse is up to date on his/her vaccinations against rabies, tetanus, and the encephalitis viruses (Eastern and Western equine encephalomyelitis, and West Nile virus).
• Establish a network and communication plan with the horse and farm animal-owning neighbors in your parish (or county, depending on where you live). Get to know one another, hold meetings to discuss various scenarios, and identify local resources for handling disaster situations. Be prepared to assist one another.
• Familiarize yourself with your parish (or county) emergency managers, who are responsible during emergencies. If you are a Louisiana resident visit gohsep.la.gov/ABOUT/STATE-REGIONS for specific contact information.
• Be sure your horse has two forms of identification: (1) Permanent identification such as a microchip, tattoo, or brand, and (2) A luggage-type tag secured to the tail and halter (be sure to use a leather halter for breakaway purposes). Fetlock tags are useful and can be acquired online or from a local farm supply store, or you can use a paint stick or nontoxic spray paint. Clearly legible tags should include your name, address, and phone number (preferably someone out of state in case of local phone outages).
• Keep a record of the microchip number (perhaps on your Coggins, which is your annual proof of a negative test for equine infectious anemia, or EIA) in an easily accessible location. It is advisable to keep a duplicate copy with a family member or friend in a distant location for safekeeping.

Evacuation Planning

• Always plan to evacuate if possible. Identify a destination and predetermine the routes well in advance. It is crucial to relocate your horses a sufficient distance from the coast—if you’re a Louisiana resident, that is preferably north of Interstate 10 and ideally north of Alexandria. Aim to evacuate at least 72 hours before the anticipated storm arrival. Avoid the risk of being stuck in traffic with a trailer full of horses and a looming hurricane. Share your evacuation contact information with your neighbors.

Emergency Preparedness

• Prepare a waterproof emergency animal care kit with all the items you normally use, including medications, salves or ointments, cohesive bandage (Vetrap or CoFlex), other bandages, tape, etc. Store the kit in a safe place where you can easily access it following a storm.
• Initiate early property cleanup to remove debris that could be tossed around by strong winds. Be careful of down live power lines that can pose a danger to people and animals.

Sheltering at Home

• The choice of keeping your horse in a barn or an open field is up to you. Use common sense, taking into consideration barn structure, trees, power lines, condition of surrounding properties, and the likelihood of the property and structure to flood. Farms subject to storm surge or flash flooding should turn their horses out so horses are less likely to get trapped and drown.
• Remove all items from the barn aisle and walls and store them in a safe place.
• Have at least a two-to-three-week supply of hay (wrapped in plastic or waterproof tarp) and feed (stored in plastic watertight containers, securing the container seams with duct tape). Place these supplies out of reach of floodwaters in the highest and driest area possible.
• Fill clean plastic garbage cans with water, secure the tops, and place them in the barn for use after the storm.
• Place an emergency barn kit containing a chain saw and fuel, hammer(s), saw, nails, screws, and fencing materials in a secure area before the storm hits so that it is easily accessible following the storm.
• Have an ample supply of flashlights and batteries and other nonperishable items.

Communications and Up-to-Date Information

• Listen to local radio stations in your area. If you have internet access, visit state-run websites that provide accurate status information (i.e., State Police, State University, Louisiana Department of Agriculture and Forestry) and take all cautions/warning serious and act accordingly.
• Visit the LSART website for more detailed information regarding horse hurricane preparations and other emergency and health-related information.  

If you’re a Louisiana resident and your animals need emergency medical care after hours, the LSU Veterinary Teaching Hospital on Skip Bertman Drive is available 24/7, 365 days a year. For pets and small exotics, call 225/578-9600, and for horses and farm animals, call 225/578-9500. While the LSU Veterinary Teaching Hospital typically remains open during hurricanes, please call first to be sure the hospital is accessible and veterinary teams are able to accept patients following a disaster. 

Healthy, well-maintained hooves can remain strong and functional for decades—supporting horses from their first wobbly steps to their final years.

Hellhole Mare was, actually, an angel of a horse. A cherished favorite among equine hoof scientists who study Brumbies—Australia’s free-roaming feral horses—the tough but gentle bay had given birth to at least 15 foals before becoming so thin and weak that researchers opted to humanely euthanize her.

When the scientists, with heavy hearts, examined this beloved matriarch, they discovered “skin and bones” and toothless jaws, says Chris Pollitt, BVSc, PhD, head of the Australian Equine Laminitis Research Unit at the University of Queensland.

One part of her body, however, showed no signs of age whatsoever—the very foundation she’d been standing on for nearly three decades. Her feet. “Nicely beveled along the edges, strong heels, no laminitis, perfect,” says Pollitt. “You’d think they’d been trimmed by a professional.”

For Pollitt and his colleagues Hellhole Mare epitomizes the equine hoof. “She was nearly 30 years old, but she had the feet of a 5-year-old,” he says, having lived in what Pollitt considers an ideal environment for natural hoof care in an unridden and freeroaming horse. “This tells us that if a horse’s foot is properly cared for, it will be perfect when the horse reaches the end of its life.”

Horse Hooves In Utero

Hooves form remarkably fast, becoming easily recognizable within 65 days of gestation, says Simon Curtis, PhD, FWCF, Hon-AssocRCVS, a farrier in Newmarket, U.K. That’s before limbs have bones, he says.

To prevent uterine damage from fetal kicks, an unborn foal develops a gelatinous horn covering. This protective layer, called the eponychium or deciduous hoof, is derived in part from the sole and white line.

The basic hoof structure fully forms before birth, Pollitt says. But because unborn foals’ hooves never bear weight, their suspensory apparatus—where the coffin bone hangs from the front hoof wall via lamellar structures—remains underdeveloped. The lamellae, which help distribute weight and support hoof function, also do not fully develop before birth. In fact, he explains that because of that lack of weight-bearing, the embryonic hoof’s first and second lamellae form a distinct crisscross pattern, positioned almost perpendicular to each other.

The First Five Months

Healthy foals usually make a wobbly stand on their hooves within the first hour of birth, and they shed their eponychium within a few hours. Pollitt says such weightbearing triggers immediate loading of the suspensory apparatus. Within a couple of days, lamellar structure angles already reflect their new loading—taking on the oblique form they maintain for the rest of the foal’s life.

Meanwhile, their tiny hooves start growing their first palmar processes—a sort of “hook at the back of the bone to which the cartilage is attached”—which are completely absent at birth, Pollitt says.

Despite these changes, though, foal hooves evolve in neither shape nor structure after birth. “The original foal hoof is a certain size—say, the size of a cup—and it can’t grow any bigger,” he explains.

Instead, new horn grows rapidly from the coronary band, at a rate of about 15 millimeters per month, to create a new, mature hoof that widens and flattens over approximately five months, says Curtis. In general, that leaves a clearly visible horizontal “birthmark” line on the descending horn.

This creates a sort of “inverse cone” by three or four months of age, with greater width at the coronary band than the bottom, he explains. That’s, in part, because the foal’s hoof wall thickens more than threefold as it grows from the top down.

Meanwhile, other structures inside the foot—bones and lamellar attachments, for example—must grow along with the horse, Pollitt adds. “Lots of things are happening inside the hoof capsule after birth,” he says. “And all of these changes have to occur in synchrony, in a coordinated fashion.”

In general, this runs remarkably smoothly, he says. “It’s marvelous to consider what—and how many—things could go wrong,” he explains. “It’s like a miracle.”

Still, things can go wrong, especially when conditions aren’t favorable to good hoof growth. Selective breeding for big bodies and small hooves, for example, can negatively impact hoof development. Rigid or oversoft terrains can as well, as the researchers have seen in feral horses.

The first few months also represent the sweet spot for club foot development. Typically, hoof horn at the heel grows faster than at the toe, which occurs especially when foals favor walking on their toes, Curtis adds. Club feet, characterized by an upright shape, long, contracted heels, and a pronounced or bulging coronary band, can sometimes go unnoticed for months or years. In his research, however, he has found they usually appear between 20 and 110 days.

In domestic settings these early months represent a critical time for skilled, frequent trimming to prevent club feet, angular deformities, and other distortions, Pollitt says.

The Rest of the First Year

As foals continue to grow, their hooves undergo significant changes as they gradually develop into the familiar adult form.

“Suddenly we see this hoof taking on the shape that we associate with hooves—which is now a truncated, oblique cone, that leans slightly backward,” Curtis explains.

The new, mature hoof structure usually lasts the rest of horses’ lives, Pollitt says.

Minor tweaks do continue. Horn growth, for example, gradually slows to around 9 millimeters per month by the horse’s first birthday, Curtis says.

Loading patterns—which start as weanlings but become more prominent as the horse’s weight increases—also come into further play, he says. Through pressure readings he found horses “don’t stand like table legs” but, rather, favor inner (toward their midline) versus outer hoof-wall loading.

Suspecting that loading was impacting natural hoof growth patterns, Curtis sought to “separate the changes horses are preprogrammed to experience versus those in response to uneven loading.” He realized the horn compresses under the horse’s weight. That means even if the hoof grows at the same rate across the coronary band, it ends up seeming shorter or longer in different parts of the hoof due to getting smashed.

As a result, the outer angles from the sole to the coronary band appear more oblique, or slanted, and give the impression that outer walls grow faster.

“Farriers recognize this, and they say it grows more hoof on the outside,” he says. “But it’s not because of the production of horn cells; it’s because of the compression.”

Dorsal (front wall) angles also change in the first year at a rate of about one degree per month until about 10 months of age, Curtis says. “So, there’s an extraordinary change in angle.”

Hooves During the Rest of Life

Once a hoof has become mature—at around 10 months of age—it changes very little in healthy horses, says Pollitt.

“My feeling is that horse’s hooves, once grown and once properly cared for and in the right environment, will virtually outlive the horse,” he says.

“A lot of people think that they age—and they’ll tell you that they do, and they’ll supply anecdotal evidence to support that,” he adds. “But my experience is that they’re a wonderful piece of evolution that serves the horse well throughout its life.”

Even so, minor natural changes occur, Curtis says. For example, hoof wall thickness increases to about 9.5 millimeters in an adult Thoroughbred, or around 11 millimeters in other breeds. And horn growth slows to about 6 millimeters per month for adults and even to 3 millimeters per month for seniors.

Researchers on an ongoing pilot study, meanwhile, seem to have confirmed what many farriers have long suspected—that with age, hoof angles continue to mildly flatten compared to the ground, Curtis says.

Still, it’s also possible older horses simply have changing hoof angles due to evolving trimming techniques, especially as owners change farriers, Pollitt says.

Despite these minor changes, though, our sources say owners often perceive age-related changes in their horses’ hooves. “It’s such a rarity that farriers find horses with symmetrical hooves,” Curtis says, and that might be in large part due to unnatural loading rather than age itself.

Age-Related Conditions

While hooves can remain strong over time, they are still vulnerable to age-related diseases and other conditions.

Many older horses suffer from low-grade laminitis, Curtis says. It is often due to excess nutrients, which weaken the laminae by altering the endocrine system, usually in combination with obesity. Besides contributing to rotation or sinking of the coffin bone within the hoof, that excess weight causes compression, especially along the sole.

Horses with age-related insulin resistance—especially related to pituitary pars intermedia dysfunction (PPID, equine Cushing’s disease) and/or obesity—can have chronic laminitic changes, Pollitt says.

That could mean they have a healthy back half of the foot but compression and changes in blood supply to the front half, Curtis says. These issues combined with a slight change in hoof angle could make the problem even more pronounced.

“As a horse ages, you might notice some changes in its hoof that are more related to age-related health conditions, such as Cushing’s (PPID), rather than changes in the hoof due to older age,” says Shannon Pratt-Phillips, PhD, a professor of equine nutrition in North Carolina State University’s Department of Animal Science, in Raleigh. “Good nutrition will still be important to support hoof health even with confounding factors such as Cushing’s or insulin dysregulation.”

Beyond endocrine disorders, geriatric horses simply have more years of impact on their feet—meaning greater chances of injury, such as to the coronary band, Curtis says. “Older horses definitely tend to have more problems, but I think it’s more a cumulative effect,” he explains. “There’s not a single problem that’s more a 20-year-old hoof compared to a 5-year-old hoof.”

Other issues might stem from a lifetime of environmental challenges—such as feral New Zealand horses navigating through rough terrain—rather than the aging itself, Pollitt says.

Likewise, aging, retired domestic horses could suffer from poor hoof health simply because they might receive less hoof care, he explains.

“A lot of people neglect their old horses,” he says. “Of course, if the environment is soft underfoot, they’ll develop long cracks, and they might be euthanized because of the condition of their feet. And (owners) say they’re an old horse with an old foot. But I don’t believe that, intrinsically, there’s aging about the hoof.”

Older horses might also experience nutritional and environmental deficits due to their decreasing social rank, says Pratt-Phillips.

“They end up standing in the mud all the time, or not getting their full ration, because the higher-ranking horses take their place,” she explains.

“Of course, the horse is old, and there will be the assumption that it’s getting old and, so, the hoof is falling away,” Pollitt says. “But in my experience many horses reach old age with hooves that are the same as when they were 3 years old.”

Take-Home Message

Hooves are phenomenal structures built to last a horse’s lifetime. Even so, they experience major changes in shape and structure through the first year out of the womb, while they adjust to bearing the weight of the foal. Once mature, healthy and properly maintained horse hooves can remain strong and functional throughout an animal’s life—provided equine veterinarians and horse owners manage all age-related diseases.

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

Understanding the important role electrolytes play in healthy performance horses

Electrolytes are minerals that break up into electrically charged ions in water. They play crucial roles in the functions of all cells and are particularly important for muscle and nerve function and fluid balance within the horse’s body. When horses sweat, they lose a significant amount of electrolytes from their body. These must be replaced for the horse to maintain optimal fluid balance, nerve function, and muscle function.

Manufacturers market a plethora of electrolyte products in a variety of forms to horse owners. Understanding when, how much, and which products to supplement is critical for optimizing equine health and performance.

Another Kind of Sweat Equity

When your horse sweats, you might see a white residue that remains on his hair coat after the sweat evaporates. Those are the residual electrolytes lost through sweat. Therefore, even by simply looking at a working horse it becomes obvious that the more he sweats, the more electrolytes he has lost. The primary electrolytes a horse loses in sweat are sodium, chloride, and potassium. He also loses calcium, magnesium, phosphorus, and sulfur, but in smaller quantities.

Don Kapper, a professional animal scientist based in Beach City, Ohio, with more than 37 years of experience formulating products, researching, and teaching in the industry, says, “Electrolytes are anions and cations (negatively and positively charged ions, respectively), so the positives and negatives must work together. When the horse runs out of cation or anion molecules the muscle will stop functioning properly. Therefore, when electrolytes are supplemented, the anions and cations must be balanced and match what the horse has lost in their sweat.”

Why Do Horses Need Supplemental Electrolytes?

Electrolytes tend to be front of horse owners’ minds in the summer months but, regardless of season, if a horse sweats, he should consume supplemental electrolytes. Sweating is the primary method of thermoregulation for working horses. Therefore, when temperatures increase, electrolyte losses are more substantial. Michael Lindinger, PhD, a former professor at the University of Guelph, in Ontario, Canada, and current president of the Nutraceutical Alliance, also in Ontario, notes, “When horses sweat, they are losing a lot of electrolytes through their skin, nearly three times more than humans. Therefore, if the horse is sweating even for just one hour, they can lose a significant amount and may become dehydrated.”

The electrolyte levels your horse needs are directly proportional to what he loses in sweat. In order to decipher how much you should be supplementing, rely on the National Weather Service’s heat index chart (weather.gov/ffc/hichart). This chart takes into consideration the day’s temperature, humidity, and work intensity level. Due to horse sweat being more concentrated with electrolytes than human sweat, it is imperative we provide electrolytes to dehydrated horses and don’t just give them water.

When a dehydrated horse receives plain water but cannot replenish electrolytes, it can negatively affect his ability to recover. “A key role of electrolytes is that they retain fluid in the body, both within cells (intracellularly) and outside of cells (extracellularly). Therefore, the only way to rehydrate a dehydrated horse is to restore hydration with a solution of water and electrolytes,” says Lindinger.

The Benefits of Supplementing Electrolytes

Lindinger, in a study published in the Journal of Experimental Physiology, demonstrated that providing a properly formulated oral performance electrolyte administered in solution at the recommended rate can delay the onset of fatigue by over 22%, reduce muscle cramping, and improve the horse’s ability to recover and perform the following day.

Kapper notes, “During this research, the electrolyte was detected in the bloodstream within 10 minutes of administration, and within 10 minutes of starting to exercise was present in the sweat.” To do this, the optimal osmolarity (concentration) of the performance electrolyte solution must be attained. The amount of electrolyte powder Lindinger and his team used was 4 ounces/gallon of water.

Indeed, to capture the benefits of electrolyte supplementation described, it is not always enough to simply provide salt and water to your horse.

Our sources don’t consider many commercially available electrolyte products properly formulated as performance products. A performance electrolyte replenishes what the horse has lost in his sweat. So if the product does not match the losses, it might not be effective for hydrating the horse, delaying fatigue, or improving his ability to recover from work.

Performance Electrolytes

The chemical makeup of equine sweat expressed as an equation is Na + K + Ca + Mg = Cl + P + S. Again, “performance electrolytes are those that emulate what has been lost in sweat,” says Kapper. “The addition of dextrose also improves the rate of absorption in the small intestine. When you are choosing a performance electrolyte for your horse, the sodium and potassium should be close to equaling the amount of chloride in the product.” You can find this information in the guaranteed analysis of the product.

Understanding ideal formulation of performance electrolytes is critical to choosing the right product for your hard-working horse. For instance, Himalayan salt and sea salt are very popular among horse owners. “However, they are very different from the electrolyte composition of sweat and, therefore, poor choices when aiming to rehydrate a horse after working,” says Lindinger.

“Supplements containing greater than 70% salt (NaCl₄) are not performance electrolytes. They are simply expensive salt,” adds Kapper.

Therefore, when shopping for an optimal performance electrolyte product for your horse, read the guaranteed analysis and compare it to the equation of electrolytes in equine sweat. Nutritionists typically recommend using salt to meet your horse’s daily sodium and chloride requirement and then adding a performance electrolyte when he starts sweating.

Consequences of Dehydration and Electrolyte Imbalance

Dehydration has a variety of negative consequences ranging from fatigue and weakness to serious health issues such as colic and tying-up. Kapper says, “Most horse owners are familiar with the skin-tent test and looking at the color of the gums when assessing for dehydration. However 14 other parameters exist that horse owners can check. The Horse Health Check (tool), developed by Art King, DVM, and Gayle Ecker at the University of Guelph, details 16 checkpoints to evaluate dehydration.”

As mentioned earlier, when a horse has lost electrolytes in his sweat and becomes dehydrated, the body will stop working properly. “Nerves and muscles will stop functioning,” says Lindinger.

Kapper adds, “The positive and negative (electrolytes) must work together so, when there is an imbalance, the horse owner will notice muscle soreness starting, more stumbling, and a shortened stride.” When considering elite performance horses that compete multiple days in a row, delaying fatigue and muscle soreness can make a significant difference in their abilities to successfully perform.

Administering Electrolytes to Horses

When selecting from the myriad equine electrolyte products and administration methods available, horse owners must understand how the horse’s body absorbs electrolytes and how they contribute to rehydration.

“All electrolytes are hydroscopic and will dehydrate your horse if they do not drink enough water after administering,” explains Kapper. For this reason, adding the electrolytes into an appropriate volume of water for dehydrated horses is extremely critical.

Additionally, he does not recommend paste electrolytes for this reason. “All paste electrolytes will lie in the digestive tract of the horse until they draw enough water from the body to break them down,” he adds.

When mixing the solution, follow the manufacturer’s instructions. “Use concentrations that are more dilute if palatability is an issue,” says Lindinger.

One of the biggest challenges owners face when supplementing electrolytes in their horses is determining how much they should offer, and if top-dressing over feed is adequate or if they need it in solution. “Feeding electrolytes as a top dressing is common, however, this should not be done for a dehydrated horse,” says Lindinger.

Providing the electrolyte in solution is the gold standard, but for horses traveling, idle, or at lower levels, top dressing the performance electrolyte on feed at the recommended amount per day is often adequate. For horses at the upper levels and exercising intensely, the electrolyte solution should be provided during and after transport to events to ensure optimal hydration prior to training and competition sessions. In addition, electrolytes are best provided within 45 minutes after training or competing.

“Relying on the average heart rate of the training session can assist horse owners in determining how much electrolyte to give,” notes Kapper. “For example, a horse that is sweating for 15 minutes during a work session will not require the same electrolyte supplementation as an endurance horse doing 100 miles per day.”

Kapper’s charts summarize electrolyte supplementation recommendations in various situations.

Supplementation Recommendations for ‘MILD’ Heat Stress Index (Below go)

Supplementation Recommendations for ‘MODERATE’ Heat Stress Index (90-105)

Supplementation Recommendations for ‘SEVERE’ Heat Stress Index (Over 105)

Tips for Supplementing Finicky Horses

When introducing a performance electrolyte to your horse’s diet, start it at home—not at an event or during travel. “Buy a small amount of the performance electrolyte and try it, especially with finicky horses,” says Kapper. If you sometimes add it as a top dressing and other times mix the product into water, Kapper recommends using the same product both places to ensure taste consistency.

“When introducing a performance electrolyte mixed with the horse’s water, start with a dilute solution and, over the course of multiple days, slowly increase the concentration to full strength,” says Lindinger. If your horse does not like one product, do not hesitate to try a different one.

Including dextrose in performance electrolytes should improve palatability. Nutritionists know that when sugar content exceeds what the body needs, muscles will weaken but, as noted earlier, adding dextrose to performance electrolytes improves absorption. Some practitioners don’t recommend adding electrolytes to feed or water because of the risk of decreasing feed consumption and causing dehydration; instead, they recommend a free-choice electrolyte. What you offer depends on the horse.

Take-Home Message

When horses sweat, they lose a significant amount of electrolytes that must be replaced to help them maintain adequate fluid balance as well as muscle and nerve function. Dehydration can be detrimental to equine health and performance. Therefore, adopt effective electrolyte supplementation strategies to promote hydration. Remember to critically review the  guaranteed analysis prior to purchasing a performance electrolyte and introduce it to your horse to consume at home prior to traveling or competing in warmer weather.

Lyme isn’t the only tick-borne illness horse owners need to consider

Lyme is the tick-borne disease most people think of first, but it isn’t the only one. Anaplasmosis is another disease of clinical significance in horses, and other diseases might be on the rise (Have you heard of ehrlichiosis in horses?). In this story we’ll look at what ticks are troublesome to horses, when and where they can be found, then discuss the clinical signs, diagnosis, and treatment of anaplasmosis, the “other” tick-borne disease that always seems to take a back seat to Lyme.

Which Ticks are Found on Horses?

In the U.S., many hard ticks infest horses, including the American dog tick (Dermacentor variabilis), the winter tick (Dermacentor albipictus), the lone star tick (Amblyomma Americanum), the Gulf Coast tick (A. maculatum), and the black-legged tick (Ixodes scapularis).

“Of particular interest to horse owners and veterinarians is the ability of these ticks to transmit disease agents,” says Kathryn Duncan, DVM, PhD, Dipl. ACVM, adjunct assistant professor at Oklahoma State University, in Stillwater, who has studied the subject with colleague Kellee Sundstrom, MS, senior research specialist. “Occasionally, a foreign animal disease, such as equine piroplasmosis, is diagnosed in the U.S. Ticks can be implicated as the cause of transmission, but the tick-borne disease agents most often transmitted to horses are through a bite from Ixodes species.” 

Where Ticks are Found

Geographically Traditionally, I. scapularis are found in the eastern parts of the United States, whereas I. pacificus are found along the West Coast, including California, Washington, and Oregon, with a few reports coming from Nevada and Utah. With continued biogeographical changes, however, the “natural” ranges of ticks are evolving, experts say, and many ticks are found well outside what has been considered their traditional geographical areas.

Sonenshine et al. (2018) reported that the main reason for expansion of ticks is climate change, notably the rapidly rising global temperatures. That said, host availability and specificity, habitat suitability, relative humidity tolerance, the extent and duration of freezing temperatures, and human impact (habitat modification) all contribute. As an example of expanding tick ranges, Sonenshine et al. noted that I. scapularis densities have also intensified in many areas, and they appear to be advancing into parts of southern Canada at a rate of about 46 km (28.5 miles)/year.

Anatomically (on the Horse) In a study on horses in northeastern Oklahoma, Sundstrom et al. (2021) looked at the types of ticks infesting horses and the preferred site of attachment. Client-owned horses residing on eight farms were examined twice monthly for one year. Researchers collected ticks from those horses and recorded the anatomic location of attachment. They included 88 horses in the study, and 84.1% of horses were infested with ticks at least once during the study period.

The median number of ticks per horse was three. Researchers identified five different tick species, the most common being A. Americanum—the lone star tick (78.2%)—followed by I. scapularis, which was much less prevalent (18.2%). They found the lone star tick most often attached in the inguinal region (groin), and they found I. scapularis primarily on the chest and armpits (axilla) of the horses.

What Times of Year In that same study Sundstrom et al. also noted ticks were discovered on horses year-round in northeastern Oklahoma with the largest number seen in May. I. scapularis predominated October through February and was still common in March.

“The belief that ticks are only out in the summer is a myth that many tick researchers and veterinarians have been trying to bust for a while now,” explains Duncan. “Tick numbers may decline in the winter, but the extent to which this happens is dependent on the geographic region.”

In fact, she says that Ixodes spp and D. albipictus prefer cooler months.

“Ticks will ‘overwinter’ in leaf litter, under snow cover, and in reservoir host habitats but reemerge when there are ample hosts available and slightly warmer days,” Duncan explains. “In order to reemerge in the spring, some stages are required to survive the winters. With milder winters and premature emergence of warm weather, we can expect ticks to be noted earlier than we’ve seen in the past. This is likely a trend that will remain based on continued tick habitat changes.”

A Look at Anaplasmosis (and Some Comparisons to Lyme)

This disease is caused by an infection with Anaplasma phagocytophilum, which is a type of bacterium in the rickettsial group. These bacteria must live inside the cells of the infected animal. With anaplasmosis, the bacteria live inside white blood cells, which are also called granulocytes. This is why veterinarians also refer to anaplasmosis as equine granulocytic anaplasmosis (EGA). In contrast, the bacterial spirochete Borrelia burgdorferi causes Lyme disease.

Similar to Lyme disease, A. phagocytophilum is transmitted to horses via the bite of an infected black-legged tick—I. scapularis, I. pacificus, and other Ixodes spp. After the bite, the tick injects the bacterium into the horse’s skin. Migrating granulocytes respond to the local inflammation and engulf the bacteria, attempting to kill them.

“But A. phagocytophilum is now exactly where it wants to be, inside the cell, where it is able to avoid natural immune defenses,” says Duncan. “Disease symptoms are caused by natural immune chemicals like interferon trying to fight off the infected cells. It takes about one week before the horse begins showing signs of disease.”

Clinical Signs of Anaplasmosis

Classic clinical signs of anaplasmosis can be as mild as the horse having a fever, depression, subtle limb edema (fluid swelling), and ataxia (incoordination).

“Many horses with anaplasmosis probably don’t show any clinical signs at all,” says Janet Foley, DVM, PhD, professor in the Department of Medicine and Epidemiology at the University of California, Davis (UC Davis), School of Veterinary Medicine.

More severe signs, which typically develop in older, geriatric horses, include loss of appetite, reluctance to move, icterus (jaundice), and petechiae, which are small pinpoint bruises on the skin.

When present, the fever is quite high, usually 103-104 F, but can reach 107-108 F and lasts for about five days.

That said, tick-borne diseases are true masters of disguise, and researchers have described various other clinical presentations. John Madigan, DVM, MS, Dipl. ACVIM, a professor in the Department of Medicine and Epidemiology at the UC Davis School of Veterinary Medicine, recently published an article describing one horse with dysphagia (difficulty swallowing) and another with respiratory distress attributable to anaplasmosis (2021).

Veterinary Diagnosis

Horses with potential exposure to ticks—essentially, those in every state in the U.S.—presenting with the above-described clinical signs, particularly a high fever, should be tested for anaplasmosis.

“A horse presenting with a high-ish fever that resides in a place that overlaps
geographically with I. pacificus would definitely make you want to test for anaplasmosis,” says Foley.

Testing includes the following steps:

• A complete blood cell count. Typical findings include either a decrease in white blood cell counts or a decrease in all three cell lines: white blood cells, red blood cells, and platelets. This latter presentation is called pancytopenia.
• Microscopic analysis of the blood cells. The white blood cells might show “cytoplasmic inclusion bodies,” which are the rickettsial organisms living inside the granulocytes.
• A polymerase chain reaction (PCR) test, a molecular method for detecting DNA of the bacterium in a horse’s blood sample.
• The IDEXX SNAP 4Dx that detects antibodies to anaplasmosis. It provides a “positive” or “negative” indication for antibodies, but it does not confirm an active infection.
• An immunofluorescence antibody test (IFAT) that identifies antibodies against A. phagocytophilum. Veterinarians must interpret this result with caution, however, because many horses living in areas where hard ticks are endemic might have those antibodies.
• Acute and convalescent titers. This is an IFAT performed when the horse is first sick to measure the antibody levels, then again two to four weeks later. The antibody levels increase about fourfold in horses that have been actively infected.

Anaplasmosis must be differentiated from other diseases. Because horses can exhibit ataxia, the top differentials include viral encephalitides such as equine herpesvirus myeloencephalopathy (EHM), West Nile virus, and the Eastern and Western encephalitis viruses. Other conditions to consider are liver disease (because of the jaundice); purpura hemorrhagica, which is a secondary complication to strangles (Streptococcus equi bacterial) infection; viral arteritis; and even the reportable and highly fatal disease equine infectious anemia (EIA). 

Treating Anaplasmosis

Like Lyme disease, anaplasmosis is easily treatable. Veterinarians’ antibiotic of choice is oxytetracycline.

“There are different treatment protocols out there, but a standard full course of antibiotics is appropriate, 10 days,” says Foley.

For more severely affected horses, practitioners can administer corticosteroids in addition to intravenous fluids and nonsteroidal anti-inflammatories.

Unlike many other diseases that fail to spare the feet, few horses with anaplasmosis ever develop laminitis.

How Commonly Does Anaplasmosis Strike?

“In Northern California, anaplasmosis is actually pretty common,” says Foley.

Duncan agrees, adding, “These infections are probably more common than we realize. But considering most horses are never tested for tick-borne diseases, we can’t know for sure.”

Nonetheless, tick-borne diseases are frequently considered as causes for disease (i.e., fever, lethargy, lameness, ataxia) in horses where ticks are endemic. But a Pennsylvania survey shows that infection with A. phagocytophilum and B. burgdorferi is not all that common even though ticks are commonly found in the state.

In that survey Thompson et al. analyzed blood samples collected from 271 horses whose veterinarians suspected tick-borne disease. The researchers used PCR to detect DNA from both bacteria and used the IDEXX SNAP 4Dx and an IFAT to detect antibodies.  

Key findings were:

• Researchers identified DNA for A. phagocytophilium in 7% of the horses. They did not find B. burgdorferi DNA in any horse;
• They detected antibodies to A. phagocytophilium and B. burgdorferi in 28.4% and 67.9% of horses, respectively;
• With IFAT they discovered antibody titers of 1:50 or more in 41.3% and 60.5% of horses for A. phagocytophilium and B. burgdorferi, respectively.

The high prevalence of antibodies to both bacteria in this survey shows that horses in Pennsylvania, where ticks are common, could have prolonged, repeated exposure to these pathogens (TheHorse.com/1118403).

“Again, though, simply identifying antibodies does not confirm that either of these bacteria are causing the disease. The presence of antibodies simply proves exposure to the bacteria,” says Foley.

The lack of B. burgdorferi DNA found in that study wasn’t surprising because the bacteria do not persist in the bloodstream for very long.

“For Lyme disease the bacteria can be sequestered in the joint, as well as any connective tissue, including kidney capsule, etc. For anaplasmosis, though, we do expect circulating blood to be PCR-positive during active infection,” says Foley. 

Identifying A. phagocytophilium DNA together with the lack of circulating antibodies in the bloodstream (the body hasn’t had time to produce them yet) and the presence of high fever or other clinical signs consistent with disease supports a diagnosis of anaplasmosis.

Emerging Tick-Borne Diseases

While Lyme, anaplasmosis, and piroplasmosis are the only three tick-borne diseases discussed in the U.S. for equids, surveys from other regions suggest Rickettsia spp and Ehrlichia spp might be clinically relevant in horses.

Therefore, Duncan et al. (2022) wanted to better understand the transmission risk of these tick-borne rickettsial disease agents.  In their study they tested ticks from horses residing in Oklahoma using PCR.

Additionally, they analyzed blood samples from horses both infested and not infested with ticks for antibodies to these bacteria.

They reported that illnesses caused by Rickettsia spp and Ehrlichia spp could be emerging tick-borne diseases in horses.

“We found that one-quarter of the ticks recovered from tick-infested horses contained DNA of Rickettsia spp, and R. amblyommatis was the most common species identified. This is part of the spotted fever group of bacteria, is transmitted by the lone star tick, and is currently considered nonpathogenic,” relays Duncan. “Ehrlichia spp were found far less commonly in ticks recovered from horses.”

In contrast, researchers did not find circulating antibodies for R. rickettsii in any of the study horses, but almost 30% of horses had antibodies for Ehrlichia spp.

“These results suggest there is a need to further explore the role of Rickettsia spp and Ehrlichia spp in equine health,” states Duncan.

The fact other diseases might also be transmitted by ticks isn’t surprising, considering ticks are known to transmit several different disease agents to humans in addition to Borrelia and Anaplasma. Examples include the agents of Rocky Mountain spotted fever, ehrlichiosis, tularemia, babesiosis, Colorado tick fever, and Powassan virus disease, among others.  

Take-Home Message

Some of the main takeaways from the current research are:

1. Many tick types can infest horses, but few are currently known to actually transmit disease to horses;
2. Tick ranges are expanding, so ticks are found in geographical ranges and at times of year they haven’t previously been found;
3. Anaplasmosis can occur commonly in certain geographic areas and should be considered as important a tick-borne disease as Lyme disease.

“If residing in a region with a heavy tick burden, be aware of practices to prevent tick-borne diseases including using regular tick control, screening annually with an antibody test, and performing thorough tick checks with proper removal,” advises Duncan.

This article first appeared in The Horse‘s Preventive Care Special Issue, which was distributed in June 2024. 

How a 21-year-old Hanoverian gelding stayed competitive at the Florida winter circuit

Many horse owners, riders, and trainers expect their horses’ athletic potential to diminish as they enter their later years; however, some horses remain healthy and happy in their work well past what many would consider their peak years. As horses age, they might experience more joint pain associated with osteoarthritis, digestive problems or a decline in gut health, or decreased performance. Fortunately, with advancements in equine medicine, veterinarians can work with horses’ trainers and care teams to help ensure long-term soundness.

The Crucial Equine Vet-Client-Patient Relationship

Successfully maintaining a horse in the top levels of competition throughout his later years requires a close relationship between the rider or trainer and veterinarian. “The rider is the person who spends the time on the horse’s back and feels differences in a gait transition or that a canter lead feels (different) one way versus the other,” says Kate Britton, DVM, of Atlantic Equine Services in Dover, New Hampshire, and Wellington, Florida.

These small details are crucial to the overall picture, especially when combined with information from the horse’s competition performance and a clinical exam. Meanwhile, don’t forget to keep the owner in the loop. “Keeping an open relationship with the owner is paramount to the health and success of the horse as they are the ones standing behind the horse with all parties involved on both good and bad days,” she adds. 

Maintaining Mindful at the Top Levels of Sport

Jennifer Hannan, rider and trainer, of Ocean Echo Farm in Wakefield, Rhode Island, and Wellington, has been training Mindful, a 21-year-old Hanoverian gelding owned by Selma Garber and Kensel LLC, since 2017. (Mindful started his US Equestrian-recognized showing career in 2013 with a different owner and riders.)

In their years together they have shown at the top venues around the country, such as Palm Beach International (now Wellington International), which Hannan says was the scene for their first international derby win as a pair. “He has since gone on to win seven international derbies at (Palm Beach/Wellington International). He has earned championships at every major horse show on the East Coast.”

Over the years Hannan and her veterinarian, Britton, have worked closely with one another to maintain Mindful’s physical and mental well-being at the highest levels of the sport.

Managing Mindful’s Joint Health

Britton regularly evaluates Mindful—typically monthly, she says, but twice monthly for performance evaluations during periods of intense competition. “Regarding maintenance care, we try to stay ahead of any issues, so (I see him) around four times per year for this.”

To manage any potential joint pain that could affect his performance, Britton treats him with intra-articular (IA) autologous protein solution and 2.5% polyacrylamide hydrogel (not at the same time) based on the results of her regular physical exams and soundness evaluations. “We try to stay ahead of any issues that may arise with his continued career, and we wanted to use the most beneficial treatments for his joints,” she says.

Equine Complementary Therapies and Nutrition

In addition to regular soundness examinations, Mindful also receives consistent veterinary chiropractic adjustments, acupuncture, and massage, which Britton says complement his medical treatments and play an important role in his longevity.

“He goes on a Theraplate daily and turns out as much as possible,” adds Hannan.

“His diet plays a role in his health as far as keeping him fit,” she continues. “We feed an all-natural diet, which is low in sugar, and I really feel like that has helped him in his career with me.” This consists of a forage-based diet (including alfalfa pellets and beet pulp) with non-GMO supplements to fill any nutritional gaps.

Utilizing Equine Fitness for Long-Term Soundness

Hannan works to keep Mindful physically fit year-round to help him maintain a healthy muscular condition and always stay comfortable in his work. “His overall fitness is our main goal,” she says. “We try to keep him fit and happy.”

Mindful stays in a consistent program with a balance of jumping and discipline-specific training days, along with relaxed trail riding and hacking days. “I think it’s important to keep him fit on many different types of surfaces,” says Hannan. “He works in the fields with hills as well as in the ring and even some harder surfaces.” However, Mindful only jumps once a week.

“That may include cavalletti exercises or just a few jumps, so he keeps his fitness,” Hannan adds, noting she rarely schools Mindful over show-height fences, but she might do so once before a show.

She adds that Mindful’s owner allows her to create a detailed training and competition plan for him, without ever pushing him past his physical or mental limits and while keeping his competition schedule light. “We have really been able to tailor his show schedule, physical fitness, and overall soundness (to his individual needs),” says Hannan. “I truly believe all of this has made a huge impact on his unbelievable career.”

Take-Home Message

Caring for horses that continue competing into their senior years demands a close relationship between the riders or trainers and veterinarians as well as careful daily monitoring of any minor changes in the horses’ behavior.

“Always listen to your horse and trust your feeling of them and what they are telling you,” says Britton. “Jenny has an exceptional ability to know minor changes in how her horses are feeling, which I feel helps keep them ahead of major issues.”

Trainers and veterinarians must maintain open communication regarding a horse’s health and performance to keep him sound and happy long-term.

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

In performance horses, every aspect of care—from nutrition and farriery to conditioning and recovery—works together to influence the animal’s long-term soundness and success. Veterinarians or equine nutritionists might recommend supplements as part of multimodal approach to support horses’ overall wellness or help manage chronic conditions. While they’re not intended to replace foundational veterinary care or good nutrition, supplements can complement a comprehensive management plan when thoughtfully selected and used in conjunction with targeted therapies and training programs.

“Supplements should only be used to augment a preexisting care plan,” says Nimet Browne, DVM, MPH, Dipl. ACVIM, of Hagyard Equine Medical Institute, in Lexington, Kentucky. “We need to understand that they are not going to solve all our problems, but they can bring out the best in our athletic partners.”

What Is a Multimodal Approach to Performance Horse Health?

A multimodal management strategy involves using multiple treatments or techniques, each targeting a different aspect of a problem (i.e., pain or inflammation). This could mean pairing a nonsteroidal anti-inflammatory drug (NSAID) with physical therapy or combining regenerative therapies with appropriate nutrition and supportive shoeing.

“By combining different modalities and agents, we hope to achieve a greater level of pain relief,” Browne says. “For example, we might use extracorporeal shock wave therapy in addition to NSAIDs to alleviate back pain.”

Because the FDA classifies only products that treat, cure, or prevent disease as drugs—requiring them to pass rigorous approval processes—most owners turn to supplements to complement the diet or fill nutritional gaps. Supplements have comparatively limited regulatory oversight, meaning owners, veterinarians, and nutritionists should thoroughly research a supplement before feeding it to a horse.

Supplements should never replace foundational management, such as proper conditioning and veterinary diagnostics. “If you’re relying on a supplement to resolve (for example) lameness, it’s very important that you first have a diagnosis so that you know what you are dealing with to know if that product might help,” says Emma Adam, DVM, PhD, Dipl. ACVIM, ACVS, assistant professor at the University of Kentucky’s Gluck Equine Research Center, in Lexington. “Supplements can complement a good program, but they are not a substitute for suboptimal training, nutrition, or management practices.”

How to Evaluate a Supplement for Horses

When choosing a supplement for a performance horse, veterinarians and owners should consider its quality, bioavailability, and clinical backing as the top priorities. “Start by consulting your veterinarian,” Browne says. “They can help identify ingredients and dosages that would help the particular problem you are trying to address.”

For example, she adds, “There are many formulations of vitamin E on the market, but many of them have poor absorption. Working with your veterinarian, you can choose the most appropriate formulation.”

Adam agrees and emphasizes the importance of evidence-based decision-making. “We can’t assume all supplements are the same,” Adam says. “I look for peer-reviewed studies or data that support a supplement’s claims. Products backed by research and developed by reputable companies demonstrate that company’s commitment to their product and to their customer.”

Bioavailability—the rate and extent to which the body can absorb and use an ingredient—can be a critical factor in a supplement’s effectiveness, says Adam. High-quality and verified ingredients, correct dosing, and a horse’s individual metabolism all affect outcomes. “If the supplement isn’t being absorbed, it doesn’t matter how promising it sounds,” she says.

Timing Performance Horse Supplement Administration

Timing of administration can influence a supplement’s efficacy. For example, owners should feed most supplements consistently to maintain steady therapeutic levels. Owners might need to give other supplements, such as those used for recovery or acute stress, around competition. “There are ingredients that help maintain athletic ability and support recovery after a tough workout,” Browne says. “These tend to have a short duration of action and therefore need to be administered closer to competition time.”

Common Equine Supplement Mistakes to Avoid

Horse owners often make the mistake of over supplementing—adding multiple products without a clear plan or awareness of potential ingredient overlaps, says Browne. “Although often not dangerous, doubling up on ingredients can lead to increased expenses and complicate feeding routines,” she says. “It can also make horses reluctant to eat or resistant to oral medications.”

However, in some cases, over supplementing might be risky because little research available to demonstrate how multiple supplements fed together can affect horses, says Adam. “Owners want to do the best for their horses and may be tempted to add product after product, but without guidance and data that strategy is inefficient at best and risky at worst.”

Choosing Equine Supplements as a Team Effort

Ultimately, effective supplement use requires collaboration between veterinarians, farriers, trainers, and owners. This includes being aware of the legal and ethical considerations around supplement use, especially in competition settings.

“It is extremely important that both veterinarians and professionals have a solid understanding of the rules and regulations set forth by the governing body of their sport,” Browne says. “These rules are in place to ensure the health and safety of the equine and human athlete.”

Adam encourages open communication between all involved in a horse’s care. “When everyone’s on the same page, the horse benefits,” she says. “Transparency helps prevent negative interactions and ensures the overall plan is coherent.”

Take-Home Message

When addressing a specific problem in a performance horse, supplements can be one part of the solution and work best when integrated into a larger strategy. Veterinarians, owners, farriers, and nutritionists should work together to create a multimodal management plan for performance horses built on transparency and including high-quality nutrition, routine veterinary care, medical management, and complementary therapies.

“Supplements can be one piece of a comprehensive care plan,” says Adam. “It’s about doing what’s right for each horse, backed by science, experience, and teamwork. Where possible use evidence-based practices rather than anecdotal experience. Always tailor choices to the individual horse’s needs and medical history.”

Editor’s note: This article was originally published in the June 2022 issue of The Horse: Your Guide to Equine Health Care.

Biologic, or regenerative, therapies have altered the way many equine veterinarians treat problematic joints. Some of the most mainstream and popular modalities they currently use to manage osteoarthritis (OA) in horses are autologous conditioned serum, autologous protein solution, platelet-rich plasma, and mesenchymal stem cells.

Most biologic therapies involve collecting and concentrating the horse’s natural anti-inflammatory and regenerative proteins or cells so they can be injected into an area of pathology (disease or damage) in the same horse.

Autologous Conditioned Serum (ACS)

Autologous conditioned serum is a cell-free extract of whole blood that has been processed to contain high concentrations of interleukin-1 receptor antagonist protein (IRAP), a naturally occurring anti-inflammatory protein within the body. It is marketed under the trade names IRAP and IRAP II.

When preparing ACS, veterinarians collect venous blood in a proprietary syringe system that encourages porous glass beads to bind with white blood cells. During an incubation process the bound white cells release high concentrations of IRAP. The veterinarian then draws the serum off into small portions and freezes it for future injection into arthritic joints. In clinical studies of ACS, researchers have reported improved synovial membrane (joint surface lining) health, stimulation of natural IRAP production, and improved lameness.

Platelet-Rich Plasma (PRP)

Platelet rich plasma is blood plasma that’s been centrifuged or filtrated to have a higher concentration of platelets than whole blood. Many horse owners are familiar with PRP and its use in tendon and ligament injuries; however, veterinarians are using it more regularly for treating joint disease.

One of platelets’ roles in the body is to modulate tissue healing. They do so by releasing growth factors and signaling molecules that initiate repair and promote anabolic (supporting tissue growth) effects. Veterinarians have capitalized on this ability by injecting high concentrations of platelets directly into damaged or inflamed regions. Because many PRP systems allow for stallside preparation, it is a convenient option for immediate treatment without the hassle of incubation or culturing in the lab, as is the case with ACS and stem cell preparation, respectively.

Historically, equine veterinarians have primarily used PRP to help treat soft tissue injuries. More recent work has led to intra-articular (in the joint) use with promising results. Although researchers have demonstrated how platelet-derived products work in vitro (in the lab) and veterinarians have seen promising anecdotal results in vivo (in the live horse), they’ve yet to produce evidence-based confirmation of its clinical efficacy.

Mark Revenaugh, DVM, owner of Northwest Equine Performance, in Mulino, Oregon, says the main factors standing between researchers’ ability to gather objective data and establish a consensus on PRP’s efficacy are the high variability among preparation systems, individual patient reactivity to the product, and an unknown ideal concentration of platelets for particular injuries.

“Most practitioners can’t always check how many platelets are being used,” he says. “Depending on the system, one veterinarian may be using 100,000 platelets/milliliter and another veterinarian may be using 1 billion platelets/milliliter. These are not the same treatments, even though both are called PRP. I would love to see an industry standard develop.”

Overall, PRP’s positive anecdotal results and relatively easy preparation make it a useful option for treating osteoarthritis (OA) in horses.

Autologous Protein Solution (APS)

Autologous protein solution (marketed under the trade name Pro-Stride) is essentially a hybrid of ACS and PRP. Its two-step stallside preparation process involves separating whole blood and sequestering white blood cells and platelets in a small fraction of plasma. The veterinarian then concentrates the separate blood components by filtration, leaving a solution of white blood cells, platelets, and serum proteins that provides the anti-inflammatory mediators of IRAP and the platelet-derived growth factors of PRP.

In a 2014 study out of The Ohio State University, researchers revealed that an intra-articular APS injection can significantly improve lameness, weight-bearing symmetry, and range of joint motion in horses that don’t have severe lameness or significant compromise to the joint structure.

Mesenchymal Stems Cells (MSCs)

Mesenchymal stems cells are adult stem cells that can direct regeneration and repair of damaged tissue. Veterinarians have used this type of stem cell as a treatment strategy for equine soft tissue injury for some time; it’s only recently that veterinarians have begun using them to treat OA, and it’s not fully clear how they work in this capacity. Researchers working on early stem cell studies hoped to establish evidence that stem cells injected into regions of injury would develop into the respective tissue. While this hypothesis proved to be incorrect, continued research has revealed that these cells might instead have anti-inflammatory effects and the ability to recruit other stem cells to the area that could, in fact, heal damaged tissue.

The two most common forms of mesenchymal stem cells are adipose (fat)-derived and bone-marrow-derived. Some study results have shown that bone marrow sources yield smaller concentrations than–but are superior to–adipose sources in their ability to differentiate into musculoskeletal tissue. Some encouraging data supporting the use of mesenchymal stem cells for treating OA exists, but researchers have only published a small number of studies with promising results. Equine veterinarians have used MSCs to treat intra-articular soft tissue injury (meniscal and cruciate damage—cartilaginous tissues and ligaments that support the stifle), with successful anecdotal results. They’ve reported more variable outcomes when using it for primary intra-articular injuries.

Carter Judy, DVM, Dipl. ACVS, staff surgeon at Alamo Pintado Equine Medical Center, in Los Olivos, California, says he currently prefers to use PRP and APS for OA treatment over MSCs. However, he admits there is much to be discovered. “What will be interesting to see is how manipulating the cells and providing them with different signals and markers can make their efficacy much more potent and focused,” he says.

Take-Home Message

When weighing treatment options for horses with OA, veterinarians should base their decision to use a certain biologic modality on its cost, availability, and how a horse has responded previously.

“Our knowledge base of how the biologics work is improving, but we are in the infancy of understanding,” Judy says. “Much of the use is based on the clinical response as much as is it on the scientific data.”

Enteroliths are a type of foreign body that can be found in horses’ intestines and are one possible cause of colic, or abdominal pain. Unlike sand or gravel, which horses ingest when they are grazing or eating outside, enteroliths develop when mineral deposits form in concentric layers around a central nidus, such as a piece of wire, small stone, twine, etc., in the large colon (the stretch of intestine between the cecum and the transverse colon). Horses can either have one enterolith (usually round and large) or multiple (often tetrahedral in shape, meaning they have angles or corners).

What Causes Enteroliths?

The cause behind enteroliths—and, especially, why some horses develop them but not others—is still not fully understood. Feeding high levels of alfalfa hay, particularly in California or other locations out west, has been associated with enterolith formation. Decreased turnout and limited access to pasture also have been linked to their development, possibly because of decreased intestinal motility or increased ingestion of alfalfa when stalled. Certain horse breeds (Arabians, Morgan horses, American Miniature horses, and Saddlebreds) have been shown to be more at risk for forming enteroliths.

Enteroliths cause problems when they get large enough that they begin to pass into the transverse or small colon. The diameter of the transverse and small colon is much smaller than the adjacent large colon, so the enteroliths become wedged. Once wedged they block food and gas from traveling out of the intestine, causing abdominal pain and signs of colic.

Some horses with enteroliths could have a history of recurrent colic (repeated colic episodes) due to enteroliths intermittently blocking the intestine and then other times allowing food and gas to pass normally. When the enterolith becomes completely wedged the horse will show signs of severe colic due to gas distension. If the enterolith is large enough and puts pressure on the intestine, it can cause necrosis of the intestinal wall in that area and lead to leakage of feces into the abdomen and secondary infection. In these cases horses show lethargy, decreased appetite, and fever, eventually progressing to signs of sepsis (a life-threatening systemic inflammatory response to infection) and shock. Due to how firmly enteroliths become lodged in the intestines, the treatment for enteroliths is always surgery.

Diagnosis

Veterinarians usually diagnose enteroliths at the time of colic surgery, when the colic signs do not respond to medical treatment, and/or the horse’s colon becomes distended with gas due to blockage by the enterolith. Abdominal X rays can be performed, but in most cases enteroliths are hidden by the large amount of tissue in the horse’s abdomen, making them difficult to detect.

Prevention

If your horse has had enteroliths before, veterinarians recommend taking preventive measures, because there is some evidence they can form again. In these cases, avoid feeding alfalfa and provide as much turnout on pasture as possible.

If at any point you see what looks like an enterolith in your horse’s manure, tell your veterinarian, because the presence of one enterolith (especially if it has a tetrahedral shape) often means there are more in your horse’s intestines. And if your horse shows signs of colic, you should always contact your veterinarian immediately.

Q. How long does it take for pasture grass sugar levels to drop after the sun goes down?

—Debra, Texas

A. The level of sugar in pasture grass varies due to several factors, including the weather, how stressed the grass is, its maturity, the time of year, and the time of day. As sun shines on pasture grass, the plants photosynthesize. This creates sugar stores the plan uses overnight to keep growing. Therefore, grasses tend to have higher sugar contents later in the day compared to earlier in the day.

Time Pasture Access Carefully

Generally, veterinarians and nutritionists recommend horses sensitive to sugar in pasture grass (such as those with insulin resistance, equine metabolic syndrome, or a history of laminitis) graze very early in the morning. It takes several hours after the sun sets for sugar levels to drop, so ideally try to avoid grazing before 3 a.m. And, because sugar levels start to build up again with sun exposure, it’s best to remove sensitive horses from pasture by about 10 a.m. If there’s significant cloud cover, you might be able to leave horses out a little longer, because photosynthesis (which relies on the sun) will be slower and therefore the amount of sugar will be lower.

One exception would be if the temperature drops below about 40°F overnight. At this temperature and below, the plants’ growth rate slow, which means stored sugars aren’t used up. As such, they’ll still be high in the early morning. In this situation, potentially at-risk horses should not have pasture access.

And, you must consider that some very sensitive horses might never be able to graze safely, while others can with careful grazing and pasture management. It all depends on the individual horse. Grazing muzzles are a very useful tool to help limit grass intake but still allow pasture access. Studies have shown that some muzzles can limit intake by as much as 80%.

Proper Pasture Management

Another important consideration is that most of the sugar in grasses tends to be in the bottom 3 to 4 inches of the plants. While it might be tempting to think that a very short, overgrazed pasture is safe because there’s “nothing out there,” such pastures present several risks—grasses are very stressed and only the lower inches of the plant are available, meaning these pastures can be very high in sugar.

As such, proper pasture management is very important to keep grasses from becoming stressed. This means horse owners need to properly fertilize and irrigate (if necessary) pastures.

It’s better for the plant and safer for the horse to stop grazing when the pasture has only about 3 to 4 inches of height left. This not only reduces sugar intake by your horse but also leaves some leaf for the plant so that it can regrow without having to dip in to root stores too heavily.

Take-Home Message

With an understanding of pasture grass metabolism and careful pasture and grazing management, many horses should be able to safely graze for at least part of the day. But, always consult your veterinarian or equine nutritionist before turning out your potentially sugar-sensitive horses on pasture.

Veterinarians routinely perform suspensory ligament branch ultrasounds during prepurchase examinations of young Thoroughbred racehorses. However, they do not have much clear data on what constitutes a normal suspensory ligament branch. Frances Peat, BVSc, PhD, Dipl. ACVSMR, of the Orthopedic Research Center, C. Wayne McIlwraith Translational Medicine Institute at Colorado State University, in Fort Collins, Colorado, collected data from 969 ultrasound exams to establish reference ranges for forelimb suspensory ligament branches. She presented the results at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Studying Thoroughbred Suspensory Ligament Branches

Peat said her goal was to define the normal appearance of suspensory ligament branches, identify common pathology, and determine any association between specific lesions and racing performance as well as association with radiographic changes in the sesamoid bones. This data could help veterinarians more accurately determine which horses are at risk of future injury or poor performance.

In total, she and her colleagues performed ultrasound exams on 593 sales yearlings and 376 sales 2-year-olds. During the exams, they assessed cross-sectional area of the medial and lateral (inside and outside) suspensory ligaments, width, periligamentous (around the ligament) tissue thickness, fibrillar pattern grade (0 to 3), hyperechoic foci (dark abnormality) grade, and sesamoid bone surface grade (yes or no).

They defined Grade 0 fibrillar pattern as a ligament with homogenous echogenicity (brightness) and uninterrupted fibrillar pattern. Grade 1 showed small areas of subtle irregularity, appearing as indistinct hypoechoic (darker) regions. Grades 2 and 3 showed moderate to severe hypoechogenicity and/or disrupted fibrillar pattern.

The researchers analyzed associations between ultrasonographic changes and racing performance from 2 to 4 years of age. Key findings relative to the fibrillar pattern were:

• The cross-sectional area of the medial branch of the suspensory ligament was consistently larger than that of the lateral branch;
• Cross-sectional area increased with fibrillar pattern grade, with Grade 3 lesions having the most enlarged branches;
• The prevalence of Grade 1 (mild) fibrillar pattern was 21% in yearlings and 29% in 2-year-olds;
• Grade 2 fibrillar pattern was seen in 8% of yearlings and 10% of 2-year-olds, and Grade 3 fibrillar pattern was seen in 1% of yearlings and 4% of 2-year-olds.

In some yearlings ultrasound data was available when they re-presented as 2-year-olds. Most of those horses (93%) either remained fibrillar pattern Grade 1 or improved to Grade 0 by the 2-year-old sale. However, one-third of yearlings with Grade 2 fibrillar pattern change progressed to a Grade 3 by the 2-year-old sale.

The Effects of Suspensory Changes on Horse Performance

Peat and colleagues also evaluated the effect of fibrillar pattern on racing performance, including eight measures of performance such as starting at least one race by 5 years of age, total number of starts, earnings per start, etc.

They only considered Grade 3 fibrillar pattern clinically important in reference to racing because those horses had a 0.8 probability of racing (i.e., an 80% chance they’d race), compared to 0.9-0.92 (a 90-90% chance) for horses with Grades 0-2 fibrillar pattern. They associated the presence of Grade 1 fibrillar pattern with significantly higher earnings per start compared to those with a higher grade.

The researchers concluded Grade 1 fibrillar pattern does not seem detrimental to racing performance—a key finding given its high prevalence in yearlings (20%) and 2-year-olds (30%). However, Grade 3 fibrillar pattern has a clinically important detrimental effect on racing.

Take-Home Message

Veterinarians frequently ultrasound suspensory ligament branches during Thoroughbred prepurchase exams but, until now, they’ve lacked clear agreement on what qualifies as normal. Researchers found Grade 1 fibrillar changes common and not linked to poor outcomes—in fact, they correlated with higher earnings per start. However, horses with severe changes had a significantly lower probability of racing. This research offers context for interpreting suspensory ultrasounds, helping veterinarians identify which horses are likely to stay sound—and which might be at risk for injury or poor performance.

Influenza in horses is typically caused by the H3N8 subtype of type A influenza virus. The H3N8 subtype circulates in equids worldwide and its infection often results in mild to severe respiratory disease. In addition to the H3N8 subtype, another influenza A subtype, H7N7, was also identified in horses in the 1950s. After a more than two-decade circulation in horses, H7N7 is believed to have become extinct, probably since 1979. In this regard, equids are unique in that only a single influenza virus, H3N8, is known to currently infect them. Humans and swine are infected by multiple subtypes of influenza A virus.

Current Knowledge About Highly Pathogenic Avian Influenza Virus (HPAI) H5N1 in Equids

Despite the consensus in the equine infectious disease research field that equids are not normally a host species of highly pathogenic avian influenza (HPAI) H5N1, very rare spillover events of HPAI H5N1 in equids over the past few decades occurred in donkeys and horses, respectively. In 2009, HPAI H5N1 was successfully isolated from diseased donkeys with influenza-like symptoms in Egypt. The antibodies to HPAI H5N1 were also detected in 27 out of 105 donkeys involved in this H5N1 outbreak. The combination of seroconversion and virus isolation data provides good evidence that equids are susceptible to infection by HPAI H5N1. Furthermore, a serosurveillance study in 2020 showed low level titers of H5 specific antibodies in wild asses (Equus hemonius hemonius) in Mongolia. Most recently, a comprehensive serosurveillance study of 2,160 equine blood samples collected from July to October 2021 from Mongolian horses, confirmed two samples positive for antibodies against H5N1 by using an array of different antibody assays. This latest serology data appears to continue a theme that equids are susceptible to HPAI H5N1 infection. Considering the low prevalence, it is very likely that HPAI H5N1 may not undergo an efficient transmission in horses, and horse-to-horse transmission may not occur.

Possibly, horses infected with HPAI H5N1 may not show any clinical symptoms. If so, despite the silent infection, HPAI H5N1 virus, when replicating in horses, may encounter seasonal H3N8 virus in the same horse. Such co-infections can create an environment to facilitate swapping genetic segments between the two subtypes and generate a new variant. Such a variant might have the transmissibility of the H3N8 parent and the virulence and novelty to the immune system of the H5N1 parent, which would enable the new virus to escape vaccination-mediated immunity, readily spread among horses, and could cause severe respiratory disease in horses and, potentially, in in-contact humans as well.

To protect equine health, HPAI H5N1 research and diagnosis in horses is critically needed so a potential threat of HPAI H5N1 can be identified before it can jump and spread in horses.

Rapid Response to HPAI H5N1’s Threat in U.S. Horses by the University of Kentucky Gluck Equine Research Center

Since late March 2024, the unprecedented spread of HPAI H5N1 in U.S. dairy cows raises critical questions about the virus’s potential to cross species barriers to infect and cause disease in other agricultural animals, including horses.

To investigate whether U.S. horses are susceptible to HPAI H5N1 infection, we and our collaborators across the country conducted a nationwide serosurveillance study involving 1,462 equine serum samples that were collected between July 2024 and February 2025. Samples were obtained from diverse geographic locations, with most samples from Minnesota, Nebraska, Kansas, Indiana and Kentucky, as well as 23 other states.

Using the IDEXX influenza nucleoprotein (NP) antibody competition ELISA, we found 653 samples (45%) tested positive for NP antibodies (produced by either H5N1 or H3N8). When these NP antibody positive samples were screened in the ID Screen influenza H5 antibody competition ELISA, we identified one sample positive for H5 antibodies. Further validation of the 653 NP antibody-positive samples with the hemagglutination inhibition (HI) assay showed that 641 out of 653 NP antibody-positive samples had detectable HI antibody titers against equine H3N8 virus, indicating these horses were previously vaccinated or infected with this subtype. Finally, none of the 653 NP antibody-positive equine serum samples were positive in the H5N1 HI assay whereas bovine H5N1-positive reference sera were successfully detected.

The current data from our study that is still in progress show that only one out of 1,462 equine serum samples is positive for antibodies to H5 antibodies, indicating that the chance of HPAI H5N1 spillover to U.S. horses is very low. Nevertheless, considering an extremely expanded list of host species that can be infected by HPAI H5N1 with fatal outcomes plus the fact that the HPAI H5N1 virus is mutating rapidly, scaling up H5N1 surveillance efforts in U.S. horses especially in regions where H5N1 has extensively circulated in bovines, is critically needed towards better understanding of equine susceptibility to HPAI H5N1 infection.

Editor’s note: This is an excerpt from Equine Disease Quarterly, Vol. 34, Issue 1, funded by underwriters at Lloyd’s, London, brokers, and their Kentucky agents. It was written by Feng Li, DVM, PhD, professor, William Robert Mills Chair of Equine Infectious Diseases at the University of Kentucky’s Gluck Equine Research Center, in Lexington.

People say good school horses are worth their weight in gold. Here’s what it takes to maintain the equine industry’s most valuable teachers.

How do you preserve your school horses’ health, soundness, and well-being long-term? This difficult question challenges every good horseman, says Jesslyn Bryk-Lucy, DVM, cAVCA, professor of equine studies and resident veterinarian at Centenary University, in Long Valley, New Jersey, where she manages the daily medical needs of the school’s approximately 85-horse herd.

Riding school owners like Nina Leeds, who runs Manor Hill Farm in Nicholson, Pennsylvania, constantly face the challenge of balancing their ponies’ and horses’ health and welfare with the financial pressures of their business. “You must do right by your equine employees,” she says.

Let’s take a closer look at the challenges and unique needs of riding school mounts.

School Horses’ Unique Challenges

Unlike a privately owned pleasure horse that’s not expected to pay for himself, school horses must earn their keep, generating enough income to cover their own care. But despite widespread stigma, a riding school job doesn’t necessarily equal subpar access to equine health care. In Bryk-Lucy’s collegiate program, where horses train and compete in the hunter/jumper and dressage disciplines, these equine professors have access to top-of-the-line care—a prime example being regular chiropractic and acupuncture treatments.

Nonetheless, these animals deal with stressors specific to their school horse status. “Inconsistency of riders is undoubtedly the biggest challenge,” Leeds admits. “These individuals must be forgiving and adaptable. Most of the time their student riders are still working on the basics and, as a result, may unintentionally sit crooked, add more pressure to one rein than another, etc.,” she says. “This can be habit-forming for the horses, causing them to travel incorrectly and creating compensatory pain over time.”

Adding to the challenge, she says, most ponies get ridden by children of varying skill levels because small, light, and experienced adult riders are hard to find.

Different Jobs, Similar Needs

Despite their occupational challenges, school horses have the same physiological needs as any other horse. “I manage the 85 school horses like any privately owned horse in my ambulatory practice,” says Bryk-Lucy, who also owns Leg Up Equine Veterinary Services in northern New Jersey. “The issues that I often have to manage—arthritis, sore backs, chronic soft tissue injuries, navicular syndrome, etc.—are the same pathologies (disease/damage) I see in private practice.”

Starting with the basics, school horses need suitable forage-based nutrition, sufficient turnout, proper grooming, regular dentistry and hoof care, and appropriate vaccination and deworming. In 2021 Bryk-Lucy’s then-student Abigail Reilly found that university horses turned out for at least 12 hours a day had a 25% lower incidence of soft tissue injuries than those turned out for less time¹. Researchers on a French study looking at 184 school horses found housing had the biggest impact on the animals’ emotionality level, a factor affecting their suitability to teach riders of varying levels². The data underscore the importance of species-appropriate care, including turnout and social contact for school horses.

Recognizing Signs of Pain in School Horses

Many school horses are hardy and stoic, making it easy to overlook signs of distress and discomfort. Pain can also manifest in subtle ways, which is why Bryk-Lucy relies on the staff and students to alert her to any potential issue with a university-owned horse. In her experience, early detection can have a significant positive effect on the horse’s recovery.

“Some common complaints that prompt an exam are an evasive response suggesting back soreness when being brushed, crabbiness when grooming and tacking, mounting block issues, reluctance to move forward, refusing jumps, favoring a lead, swapping (leads) before a jump, missing a lead change, running on the landing of a jump, tripping, etc.,” she says.

“In our lesson program we try to rule out pain as a cause of the behavior before classifying that behavior as a training issue,” she adds. In another study, the same French authors mentioned earlier found school horses were less likely to exhibit back disorders if managed by attentive caretakers who tend to overevaluate potential back pain³.

Essentially, scientists have shown attention to subtle changes in horses’ demeanors and getting the vet involved early pays off.

Limitations And Expectations

“Like most riding school programs, we have quite a few ponies that come to us as a step-down job from their competition careers with preexisting limitations,” Leeds says. She credits their long-term success to resisting the urge to push these schoolmasters when they are seemingly going so well.

“If our veterinarian has advised us that a pony should be used for flatwork only, not be longed, etc., there are no exceptions for us,” she adds. “It’s tempting when you are in a pinch, but ultimately pushing them past what is advisable, even as a once-in-a-while exception to the rule, can be detrimental to the goal of a long, productive career.”

Leeds says she’s found that teaching true horsemanship helps minimize wear on her ponies while still allowing her to run a large, successful program. Here again, setting expectations and prioritizing horse welfare remain key. “My students do not expect to jump every day, jump huge fences, or ride in extreme temperatures,” she says. “Our goal is to teach them that the animal must always come first. In turn, we can provide a more realistic workload for the lesson ponies.”

Further, Leeds emphasizes correct flatwork and small jumps with more technical exercises, and she turns to activities such as groundwork sessions and trail rides on extremely hot or cold days. For both their physical and mental well-being, she’s found it helpful to introduce variety in school horses’ work while limiting longe-line lessons because repeatedly traveling in circles adds strain to the musculoskeletal system.⁴

Money Matters

The stakes are high for the barn owner who depends on lesson income to feed and care for all her in-work, laid-up, and retired school horses and pay for and maintain the property. In France students often purchase an annual riding school pass with a fee to fund the school horses’ retirements. In the U.S. some establishments are switching from a no-commitment pay-per-lesson billing method to a semester-long subscription system, eliminating the sometimes devastating unpredictability of fluctuating monthly income. Some early adopters of the practice point out that school horses need to eat regardless of whether students attend their scheduled sessions.

We turned to Bryk-Lucy to describe the common physical limitations of school horses. “Beyond soft tissue and joint injuries, I see a lot of back soreness,” she says, pointing out that these animals typically carry different saddles and riders daily. Under her care university horses with chronic back pain get their own saddles. The rest get time off, non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone (Bute) or firocoxib, methocarbamol (a muscle relaxer), acupuncture, and chiropractic care. “These individuals usually return to work and are monitored and managed closely,” she says. However, if one needs shock wave therapy or regenerative therapies, she must refer to an outside practice, which she says isn’t always cost-effective for such a large herd.

Beyond her own expectations, Bryk-Lucy must also manage those of the faculty, staff, and students. “The reality is these donated horses are on their second or third career; they may come to us with a stiff hind end, good and bad days, etc.,” she says. As long as horses are comfortable and willing to work,and the slight gait abnormality (also called a mechanical lameness) does not worsen, she allows them to keep doing their job.

“I prepare the faculty, staff, and students to expect these individual variations in certain horses and educate them on what to look for to identify a new or worsening condition,” she says. There’s an upside, though. “Sometimes soundness issues in a low-level riding program are not as limiting as they once were on the show circuit because the horses are doing an easier job, and then I don’t have to manage anything!”

What Makes or Breaks School Horse Soundness

Bryk-Lucy says some of the big considerations that affect school horses’ ability to stay sound for the long haul include:

• Limiting rider weight to no more than 20% of the school horse’s body weight, because researchers have found exceeding this can temporarily cause lameness⁵.
• Maintaining fitness. Researchers have shown hippotherapy horses better tolerate heavier riders when fi tter⁶. “Fit horses are better able to handle their workload and less likely to sustain a soft tissue injury,” Bryk-Lucy says. “Some of our university horses are off for the summer and winter breaks. We are very careful and strategic with their return to work to ensure they are fi t enough for the first intercollegiate horse show, generally four to six weeks after the start of the semester.”
• Imposing limits on how often and how high horses jump. In a 2010 study of eight school horses, researchers in the Netherlands confirmed via blood tests what professionals already knew—jumping, even at a low level, significantly increases workload compared to cantering the same distance and speed without jumps⁷.
• Scheduling lessons so school horses have rest days and time off to recover. In 2023 researchers published data suggesting that following an increase in work hours, school horses show a greater degree of behaviors that can be interpreted as either fatigue or discomfort using the Horse Grimace Scale (HGS)⁸. Trainers must provide proper recuperation time to support career longevity.
• Choosing the appropriate level for use in a riding program, considering previous injuries, age, soundness, and suitability. “The horses that successfully work for a long time start at upper levels and slowly teach less experienced riders as they age (and need to step down),” Bryk-Lucy says. “These horses can continue to earn their keep as they age gracefully, fulfilling multiple roles as their career progresses.”
• Keeping up with maintenance as needed and addressing health and soundness issues early. At Manor Hill Leeds’ vet evaluates her ponies at least twice a year when it’s spring and fall vaccination time.

Leeds has found workload to be the most significant factor affecting a school horse’s career longevity. “Overloading an individual with a jampacked schedule risks leaving them physically sore and mentally burnt out,” she says. “Being realistic about how many students you can take with your current lesson stock is important,” she adds, tying back to the importance of keeping expectations in check.

“Pushing your lesson horses beyond reasonable risks harms both your animals and your means of making an income, potentially resulting in horses needing significant downtime and incurring vet bills,” she adds. To find the right balance, she grew her program gradually, accepting more students only as she could find more ponies to join her team.

Final Thoughts on School Horse Soundness

People say good school horses—reliable, adaptable, forgiving, and sure-footed—are worth their weight in gold. Our sources establish a few truths about the noble fourlegged teachers in riding schools: They need to earn their keep. They are athletes and should be treated accordingly, and they face unique challenges tied to their occupation. Ultimately, school horses form the foundation of our equestrian sport and deserve our commitment to a lifetime of care.

References

1. Reilly AC and Bryk-Lucy JA. Incidence of soft tissue injury and hours of daily paddock turnout in non-elite performance horses. 2021 Equine Science Society Virtual Symposium. tinyurl.com/6z75a9mw

2. Lesimple C, Fureix C, LeScolan N, Richard-Yris MA, Hausberger M. Housing conditions and breed are associated with emotionality and cognitive abilities in riding school horses. Appl Anim Behav Sci. 2011;129(2-4):92-99.

3. Lesimple C, Fureix C, Biquand V, et al. Comparison of clinical examinations of back disorders and humans’ evaluation of back pain in riding school horses. BMC Vet Res. 2013;9:209.

4. Logan AA, Nielsen BD, Robison CI, Hallock DB, Manfredi JM, Hiney KM, Buskirk DD, Popovich JM. Impact of gait and diameter during circular exercise on front hoof area, vertical force, and pressure in mature horses. Animals. 2021;11(12):3581.

5. Dyson S, Ellis AD, Mackechnie-Guire R, Douglas J, Bondi A, Harris P. The influence of rider: horse bodyweight ratio and rider-horse-saddle fit on equine gait and behaviour: a pilot study. Equine Vet Educ. 2020;32(10):527-539.

6. De Oliveira K, Clayton HM, Dos Santos Harada É. Gymnastic training of hippotherapy horses benefits gait quality when ridden by riders with different body weights. J Equine Vet Sci. 2020;94:103248.

7. Sloet Van Oldruitenborgh-Oosterbaan MM, Spierenburg AJ. The workload of ridingschool horses during jumping. Equine Vet J. 2006;38(S36):93-97.

8. Ijichi C, Wilkinson A, Riva MG, Sobrero L, Dalla Costa E. Work it out: investigating the effect of workload on discomfort and stress physiology of riding school horses. Appl Anim Behav Sci. 2023;267:106054.

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

Weighing Benefits Versus Risks

To boot or not to boot? The choice to cover a horse’s legs—and with what—­depends on many factors unique to each horse.

A main consideration is whether the horse has a specific need for protection, says Marlin, based on a previous injury, for example. Maybe he’s had issues with overreach and clips his forelimbs with his hind limbs. Or she’s got scrapes on the inner fetlocks where the opposite foot strikes. “If that shoe hits the inner fetlock just right, you can get a chip fracture,” he says.

Horses at high risk of colliding with structures other than their own feet—such as cross-country obstacles or show jumping fences taken at high speeds—also need protection. Horses hacking out through thick brush or on rocky paths need boots, at the very least to protect their skin from injury.

Hill believes it makes sense to follow the lead provided in human sports. “Human athletes use compression sleeves, tape, or braces to provide some support to areas that are unstable or a source of chronic issues, and I don’t recall those applications being shown to their detriment,” he says. Horses with chronic issues might still be able to have active careers with a bit of leg support, he says, and wrapping could help stabilize more recent injuries while they heal.

Warning Signs

Our sources agree: When used correctly, boots and wraps should only help, not harm. While researchers are still working on practical recommendations for their use, riders can take precautions to ensure these pieces of equipment aren’t causing new problems.

Polo wraps must be applied with just the right amount of tension—a skill riders can learn from experienced horse people, veterinarians, or physical therapists, says Hill. Any inflammation or swelling could suggest the wrap was too tight, he says.

Wet wraps might lose elasticity and trap moisture, putting the horse at risk of dermatitis (skin inflammation), Hill adds. Never apply a wet wrap. If the wrap gets wet during exercise, riders can complete the session, remove the wrap, and dry the leg.

As for boots, they shouldn’t slip, but they also shouldn’t be overtight, says Marlin. “Try putting an ankle bandage on, and make it really tight over your Achilles tendon,” Marlin says. “Then go for a run and see how that feels. You won’t do it to your horse again.”

Riders must also consider external factors, he adds. “The hotter the weather, the thicker the boot (especially foam or fleece types), the harder or longer the exercise, the hotter the tendons are going to get,” Marlin says.

Take-Home Message

Riders often apply boots and wraps to their horses’ legs for protection. But science still struggles to support manufacturers’ claims that boots and wraps help prevent certain injuries, and some researchers suggest they might increase the risk of tendon injury. Until evidence provides clearer guidelines, riders can aim to use properly applied boots and wraps wisely, recognizing their potential benefits and risks.

Editor’s note: This article was originally published in the Riding Horse 2023 issue.

Biosecurity measures remain a critical component to combating ‘strep throat for horses’

Teddy and the Chipmunks were brand-new additions at FarmHouse Fresh Sanctuary, in McKinney, Texas. The 15-month-old donkey and his three Miniature Horse friends were quarantined for the sanctuary’s standard 30-day period in the summer of 2023. On Day 29, feeling relieved that quarantine for Teddy and the Chipmunks was ending, the sanctuary’s team started removing the temporary fences that keep quarantined herds from touching noses with healthy resident animals.

On Day 30 the newbie herd started showing signs of equine strangles.

Strangles has been vexing horse owners since at least 1256. Caused by the bacterium Streptococcus equi, the common name “strangles” refers to the upper respiratory noise that is one of the disease’s more remarkable clinical signs. It ranks among the frequently encountered infectious diseases affecting horses.

Equine strangles is an old problem, but when it’s happening to your herd, it can feel dramatically new, changing your daily routines in an instant.

“We went on strict lockdown with them,” recalls Elise Khan, manager of the sanctuary. “Only one person would go in with them … once that person finished in the morning, they had to go upstairs and shower and change their clothes.”

Khan’s sanctuary team has been forthcoming online about the strangles outbreak. Khan says the organization’s mission to rescue animals from some of the worst situations puts her and her colleagues in a position to share information.

“It’s usually not somebody’s fault. No one would intentionally spread strangles,” Khan says. “I just feel (with) all these medical things, it would just be really comforting to me to have seen someone else go through it. And understand what to do and how to prevent it.”

‘Strep Throat for Horses’

Although it is caused by a different bacterium, “strep throat for horses” is a suitable analogy for strangles, says Ashley Boyle, DVM, Dipl. ACVIM. Boyle is an associate professor at the University of Pennsylvania New Bolton Center, in Kennett Square, teaching in the field service section. She has been researching strangles for 15 years and was the lead author on the American College of Veterinary Internal Medicine’s 2018 consensus statement regarding strangles.

But where humans can hoarsely complain about their sore throat, horses can’t articulate their discomfort.

“In horses, it gets further along before it’s recognized,” Boyle says.

The earliest sign your horse has strangles is a temperature spike. “A spike would just be an increased temperature from the normal range,” she says, which is typically 99-101.5 F. “Though sick horses are often 103 F or warmer, you should look for an increase in the horse’s normal recorded temperature.”

Other signs include a runny nose, difficulty swallowing, a “strangled” upper respiratory noise, not eating, swollen lymph nodes, or abscesses on the throat or jaw. Authors of the consensus statement report that the abscesses might rupture and drain externally or internally.

The strangles incubation period—the time from exposure to first indications of illness—can be three to 14 days, Boyle says. Once clinical signs start, they can last a few weeks.

While younger horses are more likely to be affected by strangles, S. equi can infect horses of any age. They can be exposed to the bacterium at shows, sales barns, or other places horses commingle.

PCR Testing: The Gold Standard for Equine Strangles

One of the newer developments in strangles detection and management is the use of a PCR (polymerase chain reaction) test. Now considered the “gold standard,” the PCR test can detect S. equi before a culture.

While it’s not “wrong” to test for strangles using a culture, Boyle says, it might miss the infection early on.

“If it’s early in the fever, you may not get a positive right away because they haven’t started shedding (the bacteria),” she says .

Veterinarians also need to test the correct area of the horse’s body. “They’ve heard us harp on checking the guttural pouches (blind-ended sacs on either side of the throat), but that’s actually more when you’re kind of looking to clean up the disease,” Boyle says. “The guttural pouches may not actually be positive early on in the disease.”

At the start, it might be better to get the sample from the nasopharynx (the cavity above the soft palate) via a nasopharyngeal wash or an aspirate of an enlarged lymph node.

“Those can be done with culture or PCR,” she adds. “But if you’re getting negatives and you’re still suspicious of strangles, you really should be checking with PCR.”

What You Need to Know About Guttural Pouches

If a horse has chondroids(firm balls of pus) in his guttural pouches, the S. equi is contagious. “That’s what makes the carriers and what makes the risk of infection keep going even if you have got all the clinical signs down in the herd,” explains Alberte Fridberg, DVM, of the University of Copenhagen’s Department of Veterinary and Animal Science and Ansager Equine Hospital, in Denmark. To look for chondroids in the guttural pouch, your veterinarian will use a scope and flush the area.

When a “persistent carrier” continues to shed the bacteria into common areas like water troughs, a strangles outbreak can seem to be waning, only to flare back up again, making the outbreak last longer.

Equine Strangles Vaccination Strategy

In the U.S. there are two strangles vaccines you need to know about, Boyle says. There is an intramuscular vaccine and an intranasal vaccine.

Both vaccines provide protection against S. equi. A benefit the intranasal vaccine offers is that it provides immunity at the location where bacteria enter the horse, Boyle says. Meanwhile an intramuscular vaccine given to the dam prior to parturition (birth) can provide protection to a suckling foal.

Strangvac, which is available in Europe but was still awaiting USDA approval as of November 2023, has the attention of Fridberg, who was still a veterinary student when strangles captured the attention of Denmark’s horse community during an outbreak. She was inspired to work on an article outlining strangles hygiene, which was ultimately published in 2023 in Equine Veterinary Education.

Fridberg says she finds Strangvac interesting because of its DIVA—differentiating infected from vaccinated animals—capabilities.

“We were missing that in some of the others,” Fridberg says. “That’s an important ability of a vaccine.”

Vaccine timing is important.

If your barn is in the middle of an outbreak, you’ll have to wait before vaccinating, says Boyle. That’s because some horses are hyper-responders and can develop purpura hemorrhagica (an immune-mediated inflammation of blood vessels causing swelling of the belly and limbs and bleeding noted on the gums) after the vaccine. For the same reason, you’ll need to be cautious about vaccinating horses known to have had strangles in the past. Your vet might recommend running a titer to check your horses’ immunity to be sure they aren’t at high risk of being hyper-responders.

Isolating the Sick Herd

When equine strangles strikes, put up the fences. Isolation is key because the bacteria spread through close contact and shared equipment.

“It’s easier said than done,” Boyle acknowledges. “And I so appreciate that. But it’s so, so important.”

Exactly how you’ll isolate your horses will depend on your facilities. On some farms, that might mean the barn becomes the sick ward, and the pastures are for horses without clinical signs. On other farms, that might mean turning a run-in shelter into a stall and adding a double fence perimeter to the shed so horses in the rest of the pasture can’t touch noses with the sick horse.

The team at FarmHouse Fresh Sanctuary, which faced two outbreaks in six months, designated one pasture for healthy horses. The pasture beside it was for sheep on one side and goats and donkeys on the other. The third pasture was for sick horses.

“None of them could touch noses,” Khan says. “The goats can’t get strangles, but let’s say (a sick horse) sneezed and a goat stepped in it and then walked over to a healthy horse. A healthy horse could get it (from coming in contact with the nasal discharge). So that’s why we got really strict.”

Checking Temps, Cleaning Buckets

Once you’ve established your quarantine area, look at hygiene considerations such as shared equipment, temperature checks, and personal protective equipment.

Shared water sources provide an opportunity for exposure to S. equi; each pasture and stall should have its own water source with no cross-contamination—don’t swap out buckets and don’t let a hose dip into the water of any bucket or trough and then dip it in the next.

You’ll need to clean, disinfect, and dry buckets and other shared materials. Don’t skip the drying process.

“The bacteria love wet environments,” Boyle says. “That’s been shown in studies.”

Also, remember the human element. You’re a possible disease “fomite.” The concern isn’t your snot; it’s the snot on your sleeve or slobber from a sick horse, much like the goat scenario Khan described (the goat could’ve acted as a fomite, too).

If you are managing a strangles outbreak, expect to do a lot of laundry. It will be up to you how you manage that; maybe you’ll elect to have personal protective equipment such as Tyvek suits. Maybe you’ll wear different clothing around different herds. Maybe you’ll have different personnel handle sick horses. You might also add a disinfecting foot bath station and hand sanitizer pumps.

For the most part, washing machines work well at killing off the bacteria. But beware of nylon halters. In a Swedish study, researchers found the bacteria survive on nylon halters even after going through the machine, Boyle says. It might be best to throw nylon halters away after sick horses wear them.

Though the long incubation period associated with strangles can be daunting, temperature checks are your best hope.

Catching a jump in temperature can allow you to move the horse to isolation before it starts shedding a lot of bacteria.

“That’s the way to stop the outbreak,” Boyle says.

She recommends twice-daily temperature checks for every horse on the farm during an outbreak, but stresses that making temperature checks a part of your regular horse care routine can make it easier to catch even illnesses besides strangles.

“Anyone who had a fever of over 102.5 degrees would go straight over to the quarantine,” Khan says of the farm’s second outbreak. The team would then clean and sanitize the horse’s stall and equipment. “We also took notes on their discharge from their nose because our vet tells us you’re basically looking for … banana pudding consistency.”

The long battle with strangles has Khan taking a different approach to biosecurity. She’s extended the quarantine period for new additions to 35 days and is adding a pharyngeal wash for testing to new horses’ standard care before being released into the herd.

If your horse comes down with strangles, your veterinarian might or might not recommend antibiotics. It will depend on how sick your horse is. Horses that get antibiotics for strangles might not develop strong immunity to S. equi and could be reinfected, per the 2018 consensus statement.

Take-Home Message

Regularly checking your horse’s temperature can help you catch equine strangles early.

Strategize now for how you will separate infected, exposed, and healthy animals on your property. Build or buy any infrastructure you might need, such as temporary fencing or extra water troughs. Finally, talk to your veterinarian about vaccinating your horse against strangles.

Further Reading

Fridberg, A., Adler, DMT, Jørgensen, M.G. & Olsen, R.H. (2023) The hygienic aspects in the management of strangles. Equine Veterinary Education, 35, 540–550. Available from: https://doi.org/10.1111/eve.13794.

Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS, Buchanan BR. Streptococcus equi Infections in Horses: Guidelines for Treatment, Control, and Prevention of Strangles-Revised Consensus Statement. J Vet Intern Med. 2018 Mar;32(2):633-647. doi: 10.1111/jvim.15043. Epub 2018 Feb 9. PMID: 29424487; PMCID: PMC5867011.

Greater awareness and ongoing research mean fewer foals are being born with this genetic skin condition

Attention stock horse owners: Have you heard of HERDA? For the past 20 years, learning about hereditary equine regional dermal asthenia (HERDA) has been a major goal of stock horse associations and HERDA researchers alike. Up to 3.8% of Quarter Horses—and specifically up to 28.3% of those in the cow horse population—are carriers for this debilitating genetic condition that causes horses’ skin to wrinkle, stretch, and slough. While HERDA horses can be maintained with specialized management, most affected animals are euthanized due to the impracticalities of that care, the inability to be ridden, and painful scarring.

With simple genetic testing, though, owners can find out if their animals are affected by or carriers of HERDA so they can make sound management and breeding decisions. As awareness increases, the industry should see fewer foals born with HERDA—and aim to eliminate clinical cases altogether.

How HERDA Happens

In 1978 scientists first described an unusual super-elastic skin condition and suspected it might have a hereditary link. They were right: In 2007 scientists discovered HERDA arises from a simple mutation on a gene called PPIB, located on Chromosome 1. If a foal inherits that same mutation from both parents, he or she will develop clinical signs of the disease, says Rebecca Bellone, PhD, Veterinary Genetics Laboratory director and a professor at the University of California, Davis.

Scientists traced the mutation back to its origin, a 1944 foundation Quarter Horse colt named Poco Bueno, who sired 405 registered foals. The stallion possessed mutated genetic codes for defective collagen processing. Collagens build connective tissues in skin as well as in cartilage, bones, tendons, ligaments, neurological membranes, and some other tissues. The most obvious effect of these defects is abnormally stretchy and wrinkly skin, with layers often detaching from each other so the skin peels away and sloughs. These gaping skin wounds—along with any other contact wounds—heal slowly and poorly, leaving disfiguring scars.

Owners might first notice frequent lacerations, cuts, or scrapes on young horses eventually diagnosed with HERDA, but the strongest clue appears when these animals are first saddled. At this point they often start to develop wounds along the back and neck. Ultraviolet rays from the sun seem to make the condition even worse, creating new lesions and exacerbating existing ones.

However, because horses have connective tissue throughout their bodies, they might also develop problems elsewhere, says Abby McElroy, DVM, MS, PhD candidate and researcher at the University of Massachusetts Chan Medical School, in Worcester. In particular, researchers know HERDA to be associated with an increased risk of corneal ulcers as well as abnormal heart valves, she says.

“If you have an affected horse, it’s obviously very serious for both the horse and the owner,” says Tammy Canida, registrar at the American Quarter Horse Association (AQHA), whose headquarters are in Amarillo, Texas. “The humane thing to do is put the horses down in most cases.”

It Just Takes Two Alleles

Early research in 2009 revealed 3-4% of Quarter Horses, Paint Horses, and other stock horses probably have the HERDA mutation. However, most of these horses show no signs of disease because they’re merely heterozygous carriers, meaning they have only one copy of the HERDA mutation.

Genetic material comes from both parents equally, as genes from the mother line up in the DNA on the chromosome with matching genes from the father, Bellone explains. Genes often exist in alternate forms, which are called alleles. If an individual gets a different allele from each parent for the same gene, he or she is heterozygous for that gene. If the alleles are the same, though, the individual is homozygous.

Because HERDA is recessive, horses must have acquired the mutated allele from both parents—meaning they’re homozygous—to show clinical signs, Bellone says. Therefore, horses that acquire the mutation from the dam or the sire alone are heterozygous and seem perfectly healthy. Meanwhile, they’re carrying the DNA for the disease. If heterozygous horses are bred to other heterozygous horses, their offspring could inherit the mutated allele from both parents, Bellone says. The resulting cross has a 25% chance of producing a homozygous individual—one with clinical HERDA.

Before 2007 breeders sometimes used trial and error to identify silent HERDA carriers in their breeding stock. But since the development of the DNA test for the HERDA allele, breeders have had a simple tool for recognizing carriers, Bellone says.

“That’s the thing about HERDA; it’s recessive,” she says. “So you can avoid producing an affected animal by knowing what the genotypes of the parents are.”

High-Performance HERDA Carriers

If there’s a DNA test for HERDA carriers, why wouldn’t we just sterilize all mutant-gene horses and eliminate the allele entirely?

The answer might be due to an ironic HERDA twist. As it turns out, there might be a link between a single HERDA allele and good athletic performance. In fact, three of today’s top cutting horse sires are HERDA carriers, says McElroy. So the demand for these genetic lines remains high. And that’s no secret to the AQHA.

“It seems to be in popular lineages that are performing well in the industry,” Canida says.

The reason for that link remains a mystery, says McElroy. “I think that’s a big question within the industry: Why are there so many super-performing carriers?” she says, adding that research is lacking.

Some people in the stock horse industry suspect the mutation might code for more joint mobility in heterozygous horses without causing the deleterious effects of the gene, she explains. “Maybe they have a little bit of the phenotype,” she says, a technical term for observable characteristics.

McElroy wonders if subtle changes in connective tissue might improve performance in athletes in general—both horse and human. “You look at swimmers and gymnasts, for example,” she says. “They’re obviously incredibly hypermobile. But they’re not ill. And for horses working in cutting and reining, that hypermobility would give them a huge athletic advantage.”

Even so, if the allele endows stock horses with a “superpower” that garners many winnings early in the horses’ careers but then leads to bone and joint conditions such as osteoarthritis later in life, it could pose a welfare issue, McElroy adds.

Thus far, scientists have neither studied these questions nor measured the degrees of equine or human joint hypermobility with regard to connective tissue quality. And there has been no research completed on bone and joint health specifically in HERDA carriers. “That’s something that really needs to be studied, in my opinion,” McElroy says. “At this point, it’s unclear if an athletic advantage truly exists. It’s also unclear if any perceived advantage comes from the HERDA mutation or another gene.”

DNA Testing: Quick, Easy, Affordable, and Important

With HERDA carriers’ successful performance careers and breeding popularity, genetic testing has never been more important, our sources say. “The number of carriers right now is astronomical,” McElroy says. “So people really need to make informed decisions before breeding.”

The AQHA and American Paint Horse Association (APHA) agree. To minimize the breeding of homozygous foals, the associations have teamed up with Bellone and other experts to create educational materials and offer easy instructions for owners to have their horses’ DNA tested. A simple HERDA DNA test requires a few strands of mane and costs $45 through the UC Davis Veterinary Genetics Laboratory, or $100 as part of the full AQHA/APHA genetic testing panel.

Since 2015 the AQHA has required that owners of all breeding stallions have their studs’ genetic HERDA information on file and accessible to mare owners. In 2018 the APHA followed suit. Foals can only be registered with the AQHA and APHA if their sires’ genetic information, including HERDA status, is on file with the association.

Being heterozygous doesn’t exclude the stallions from breeding, however. Canida explains that the goals of the test are purely informational. “We always recommend that mare owners ask stallion owners for the information that would impact their breeding choices,” she says. “But we also make it public information, so that they can always pull the record and see it on our files as well.”

The associations do not require owners to test broodmares, but they strongly encourage it—especially when considering breeding to a heterozygous stallion. “If mare owners are aware that the stallion they want to breed to is a carrier, then they need to test the mare to ensure that they don’t produce any affected animals,” Bellone says.

 “We feel that our goal is to educate the members about it so they can make the choices for their breeding barn,” says Canida. “We just want them to be aware of what a horse may or may not have.”

“And under current rules, it will not be eliminated,” she adds. The AQHA’s focus, she says, is on education so as “to avoid getting those (clinically) affected horses.”

Meanwhile, nonbreeding stock can also undergo DNA testing if their owners suspect they’re homozygous or even heterozygous for HERDA, or if they’re just curious, our sources say. Both the AQHA and APHA websites provide educational tools that help owners understand DNA test results and how to manage their horses accordingly.

Importantly, awareness—even of the tests themselves—remains key, stresses Bellone. “If the genetic test exists, but people aren’t using it, it’s not helping,” she says.

Managing (and Surviving) HERDA

While the main goal is preventing the birth of any homozygous foals, the harsh reality is such births persist, our sources say. Our sources say most affected adult horses end up being euthanized, some are shipped for slaughter, and a few are rescued by nonprofit organizations. Some homozygous mares serve as embryo transfer recipient mares. Occasionally, owners keep their own homozygous foals as well-protected pets. McElroy says she recalls the case of a homozygous horse that successfully worked cattle for eight years—although it’s possible the horse had, for reasons unknown, a milder form of the disease.

If their quality of life permits it, HERDA horses could be kept in indoor conditions during daytime hours to prevent sun rays from breaking down collagen, she says. Owners would have to ensure the environment is low-risk for contact injuries—even rubbing against surfaces—and for insect bites. “There are owners who have kept these horses going for many years, keeping them inside during the day, turned out at night with intensive fly management, staying away from … anything that’s going to traumatize the skin,” McElroy says.

Management methods for similar connective tissue disorders in humans and smaller animals have progressed in recent years because these individuals’ environments can be more easily controlled. Unfortunately, that’s not the case for horses. “We just don’t know much about keeping these horses going longer,” she says.

“At this point, we don’t have a lot of therapies or treatments,” McElroy says. “It would really just be intensive management.”

HERDA on the Horizon

In the past two decades, HERDA researchers have mostly studied the condition’s effects on the skin, but they’ve started looking into its effects elsewhere in the horse’s body. For example, homozygous horses have thinner corneas with more frequent ulcers, and they have weakened heart valves.

“Collagen is everywhere, so it affects every bodily system,” says McElroy, who studies HERDA as an equine model for Ehlers-Danlos syndrome—the general HERDA analog affecting humans, rabbits, cats, dogs, cattle, sheep, and mink. “There’s a lot we don’t know about. Do they have bone fragility? What’s going on with their GI tract? Are they more likely to colic? Are they more likely to have bladder ruptures as foals?” Her own work has focused on the nervous system and confirms—like in humans with Ehlers-Danlos Syndrome—HERDA horses have abnormal spinal cord regions in the sacrum area, although the physical implications remain unclear.

Scientists are also considering whether HERDA affects some horses more severely than others—with some, like the exceptional HERDA working cow horse, having such mild disease it might even go unnoticed. “For me the question has always been, ‘Are there some underlying genetics that can protect some horses?’ ” Bellone says. “And also, ‘Is there any hope of testing for something like that, or doing any kind of research on it?’ ” To her knowledge, at this time, there is not.

An upcoming research area for such diseases is gene therapy, which essentially involves injecting the healthy allele via a viruslike vector into newborns, effectively replacing the bad allele, McElroy says. Better yet, gene therapy could start after genetic testing of the embryo. While progress is underway for humans, the astronomical price of such therapy—reaching seven figures—is likely to preclude its commercial use in horses. “It would be more like on a research basis,” she says, adding that costs might drop over time and especially with prenatal treatment.

Meanwhile, scientists and associations are continuing to focus on awareness, making sure owners understand what HERDA is and how to prevent it through DNA testing and wise breeding. Efforts so far have been fruitful, McElroy adds, with a drop in the number of homozygous foals born.

Whether the incidence of the allele itself is dropping remains hard to say, notes Bellone. With the steep increase in testing, it’s difficult to compare today’s rates with those from the mere hundreds of horses tested 15 years ago. Even so, ongoing analyses suggest there’s a trend toward a drop in allele frequency, she explains.

“We need to continue that push for education and make sure that people really understand the genetics of a recessive disease, and make sure they understand the risk of carrier-to-carrier matings,” McElroy says.

Take-Home Message

As scientists progress in their understanding of HERDA, so must the owners and breeders managing and producing the horses that carry the alleles responsible for this recessive disorder. With improved awareness and ongoing investigation into the whole-body effects of this disease, the industry is striving toward prevention and—potentially in the distant future—a hope for therapeutic management.

This article was originally published in the April 2020 issue of The Horse. 

Q. Does dressage have a positive or a negative effect on a horse’s neck and back and his comfort and overall health?

A. As most dressage trainers know, the answer depends on the skill and fitness of both the horse and the rider. With dressage, the rider is trying to accentuate natural movement patterns, while at the same time inducing head and neck positions and collective movements though set gait patterns. This can appear to be quite easy for some horses and their riders but much more problematic for others. Physical fitness requirements for both horse and rider include strength, core stability, and flexibility. Neck and back pain have negative influences on these attributes. Repetitive-use injuries are common in any equine athlete. Excessive caudal cervical extension can predispose to cervical osteoarthritis. Heavy or unstable riders can aggravate existing impinged thoracolumbar spinous processes and hind-limb lameness. The improper use (of tack) or ill-fitting tack also contributes to neck and back problems. In any athlete the constant reassessment of equipment, modifications in training, and use of preventative care is needed to maintain athletic conditioning and performance.

In general, the horse-rider skills required in dressage provide a good foundational training across all equestrian disciplines. No matter the ridden activity, dressage provides the basic skills required to develop healthy horse-rider interactions, coordinated movement patterns at controlled speeds, and induced collected movements. Conversely, a lot of horses used in dressage can also benefit from cross-training during extended hacks, long-line work, or exercise over ground poles and small cavalletti.

Where we get into problems is when riders do not put in the required time or incorporate the needed skills for proper training. Several studies have reported that most owners do not recognize neck or back pain in their horses and are not able to determine if their saddle fits appropriately or not. If these common issues are overlooked or not recognized, then continued ridden exercise can be detrimental. While this problem is not limited to dressage, asking horses to work through their pain is not productive and is often harmful. Any activity that is done too long, too intense, or too frequent can predispose a horse to fatigue and injury. Like us, a good balance between work and time off is needed to maintain health and well-being.

Equine nutritional supplements have become so popular that many owners view them as staples rather than simple additives. Further, manufacturers have designed and marketed these supplements so successfully that horses often receive several products per day to manage various conditions. For example, one study reported that certain populations of competitive horses receive about four nutritional supplements a day (Williams CA et al., 2012).

Offering multiple nutritional supplements can have a number of outcomes, not all of which are beneficial:

1. Your horse flourishes at the hands of supplementation, benefiting from targeted nutrition strategies.

This is an ideal situation. Having your veterinarians evaluate your horse’s physical condition frequently and reviewing his diet will help achieve the maximal response to any supplementation regime.

2. An oversupplemented horse receives an excess of certain nutrients.

While this approach might address several health issues simultaneously, nutritional supplements are expensive, making offering excessive nutrients uneconomical. Further, dietary imbalances might develop secondary to oversupplementation that can potentially result in deleterious nutrient interactions. A classic example of this is vitamin E—a popular nutritional supplement. High levels of vitamin E can lower systemic beta-carotene levels, which can potentially result in a vitamin A deficiency. Further, excess nutrients excreted in urine and feces negatively affect the environment.

3. You don’t see any response.

In this case you must take a step back and critically assess the situation. Is your horse not responding because the diagnosis is incorrect and you are supplementing the wrong product? Or is the product you are offering not up to snuff? In other words, does your selected supplement actually contain the type and amount of ingredient listed on the product label? Because the U.S. Food and Drug Administration (FDA) doesn’t regulate nutritional supplements, poor-quality supplements can surreptitiously infiltrate the market.

When choosing a quality supplement, follow the SMART supplementation strategies:

S—Shop Around. Do your research to identify a quality product most likely to contain the type and amount of active ingredient the label claims. When comparing products, use the ACCLAIM system:

• A name you recognize? Do you recognize the manufacturer? Look for products manufactured by established companies that provide educational materials for veterinarians and consumers.
• Clinical experience. Companies that support clinical research and test their products for safety, efficacy, and bioavailability with results published in peer-reviewed journals are more likely to have quality products.
• Contents. The product label should include all active and inactive ingredients/fillers.
• Label claims. Supplements with realistic label claims based on scientific study results, rather than testimonials, are preferable. Avoid products with illegal claims to diagnose, treat, cure, or prevent a disease.
• Administration recommendations. Look for products with clear administration recommendations with the recommended dosages based on published clinical trials.
• Ingredients. Products with some form of pre- and/or post-market surveillance in place and companies that have voluntarily instituted current Good Manufacturing Practices (cGMPs) and other quality-control and -assurance techniques are more likely to be reputable.
• Manufacturer information. This should be clearly stated on the label, preferably in concert with contact information or a website for customer support.

M—Monitor Response. Nutritional supplements can take effect immediately or might require prolonged administration prior to having a notable response. Always watch for adverse effects.

A—Avoid Double Dipping/Mixing. Many drug-nutrient interactions can affect the way horses’ bodies metabolize exogenous substances. Offering several medications or supplements might result in unexpected side effects.

R—Re-evaluate Your Choices. If the product is not having the expected effect, consider alternate dosing, sources, or management strategy.

T—Talk to an Expert. Always consult your veterinarian before using any new supplement.

Originally designed for joint supplements, these strategies can be adopted to any nutritional supplement to help horse owners get the most bang from their hard-earned bucks.

How to manage leg lacerations that require bandaging

The dribble of blood down your horse’s leg certainly puts a damper on your morning riding plans. Taking a closer look, you see the culprit is more than a scrape, as the wound extends into deeper layers of the skin just above the fetlock. It doesn’t look bad enough to need sutures, but you do want to keep it clean and help it heal. So, aside from postponing that ride a few days, what do you do?

First and foremost, call your veterinarian or text a photo of the wound so he or she can gauge its severity. Wounds near joints risk contaminating the surrounding synovial structures and warrant professional evaluation. Otherwise, your veterinarian can guide your next steps.

Here we will take an in-depth look at wound care—specifically for when the injury is on a horse’s leg.

Cleaning a Wound

If you have a horse that is accepting of you touching and probing a wound, then you might be able to remove debris and contamination simply with a good cleaning job.

“Any lavage (washing or flushing out) is fine, even if you just use tap water,” says Erin Denney-Jones, DVM, owner of Florida Equine Veterinary Services, near Orlando. “Sterile saline with or without (the antiseptics) Betadine (povidone iodine) or chlorhexidine solution is great, but usually all an owner has available is a garden hose to spray the wound.”

When using antiseptic solutions, it’s best to dilute them because full-strength concentrations are toxic to the tissues you’re trying to treat. For dilution, add 20-25 milliliters of chlorhexidine or 10 milliliters of Betadine per quart of water. 

“Don’t use hydrogen peroxide, as it is known to displace and kill cells and also causes pain when applied, so a horse could become quite reactive,” says Denney-Jones. “Peroxide has a good role for cleaning blood off the leg (not directly on the wound) or from clothing.”

Once you’ve removed the bulk of contaminants, you can then gently clean the wound with antiseptic soap (chlorhexidine or povidone iodine) if your horse allows. It is important to rinse thoroughly to prevent the soap from damaging the skin’s keratin cells.

Conversely, if your horse has a hissy fit if you even attempt to look at his wound, then you’d be safer just spraying it with a hose or waiting until your veterinarian can tend to it. No wound is reason to risk getting hurt.

Check your records to be sure your horse received his most recent immunization against the life-threatening disease tetanus within the past year. If you don’t know your horse’s immunization status, have your veterinarian boost the vaccine using tetanus toxoid.

We’ll continue this article assuming your horse is willing to allow you hands-on access to his wound.

Bandaging the Wound

Once you’ve cleaned the wound as best as possible, let it air dry while you gather your bandaging materials. Denney-Jones recommends bandaging all wounds that are more than an abrasion or a scrape and located below the knees or hocks to help reduce swelling. A bandage serves several purposes:

• Protection from contamination and insects;
• Tissue support;
• Stability; and
• Warmth.

All these ingredients help create an optimal environment for healing. While it’s difficult to impossible to speed up healing, there are many ways to slow or compromise it. The objective is to “do no harm.”

​“My go-to bandage (if the wound is contaminated) is to use a wet-to-dry application,” says Denney-Jones. “Using dilute Betadine or chlorhexidine, lightly soak gauze, place that directly on the wound, and then wrap appropriately. At the bandage change the damp gauze debrides the wound, which is then wiped gently to remove moisture or discharge. The tissue then looks clean and ready for a new bandage application.”

Another technique involves applying water-soluble antiseptic salves and a nonstick dressing to the wound, covering it with padding, and applying sticky bandage material to hold it all in place.

In some cases, such as in wet, rainy, or snowy environments, it helps to apply a double bandage to keep the inner layer dry and contaminant-free for as long as possible. This means applying a bandage over the wound, then applying another, less-bulky bandage over the first one.

Denney-Jones practices in a subtropical climate, which is much more humid than where I reside in Colorado and makes for unique differences in wound ­management.

“Our warm and moist environment favors bacterial and fungal growth, which interfere with wound healing,” she explains. “We also have a problem with pythiosis (a skin infection) if a horse ­immerses a wound in a pond or lake when they go for a drink. The nickname for the skin problem is ‘Florida leeches,’ although it is (caused by) a fungal organism that is more aggressive than summer sores (habronemiasis caused by skin deposits of Habronema stomach fly larvae) and difficult to treat. With that in mind, if a wound is bandaged or if there are any open sores, it is best to keep those areas clean and dry and lock the horse away from water sources such as ponds and creeks.”

Bandage Change Frequency

How frequently you change your horse’s bandage depends on the environment and the amount of wound discharge. “We change bandages daily at first, especially with seeping wounds because moisture is trapped beneath the bandage,” says Denney-Jones. “Once the wound progresses in its healing, we change it every two to three days. Sweat and skin sloughing create a gummy superficial discharge that is wiped clean with dilute chlorhexidine on a gauze pad.”

Don’t continue scrubbing a healing wound, however, as it can prevent skin cells from successfully populating the wound bed.

If you don’t have access to a clean surface for a bandage change, stand the affected limb on a towel, blanket, or sheet to eliminate soil and manure ­contamination.

Topical antiseptic salves can help keep tissues moist and pliable, while powders and sprays tend to dry tissue out, which is counterproductive in drier climates. Water-soluble products are best because they don’t hold in heat like petroleum-based ointments do, and you can wash them away easily. Only apply petroleum-based salves on the skin below a wound to prevent scalding from seeping serum. Be sure to talk to your veterinarian about what salve would be most appropriate for your horse’s wound.

“If a wound is sutured,” says Denney-Jones, “bandaging for the initial three to five days helps to decrease swelling and also deters a horse from chewing at the wound and removing the stitches.”

Anyone who has had to care for a wound that requires bandaging for extended periods knows how expensive this can be. Reusable bandaging materials are commercially available and can help cut down on costs at each bandage change.

You can stop bandaging once epithelial tissue (the basis of skin) forms across the entire wound. I like to keep a wound bandaged until it is about the size of a quarter and has a nice pink epithelial layer across it. Then, a protective spray such as an aerosol bandage (e.g., AluSpray) keeps flies away and protects the wound from dirt. In some situations, such as in moist climates, spray medication might trap sweat beneath, says Denney-Jones, whereas in drier climates it can be helpful.

Bandaging Techniques

As you put on a bandage, apply light compressions to help deter proud flesh and swelling. Denney-Jones advises owners to be aware of bony prominences (sesamoid bones, carpal accessory bone at the back of the knee, the point of the hock) when bandaging. Protect these areas with cotton padding before applying a bandage; otherwise, the pressure could create difficult-to-heal sores.

Use cotton quilts or roll cotton padding along long bones and over joints to create a snug bandage that doesn’t compromise blood supply or tendons. Pull bandaging material across the front surface of long bones and joints while laying (not pulling) it across the back tendinous surfaces. If cotton or quilts aren’t available, feminine hygiene pads or baby diapers can serve as useful padding to protect skin and tendons from bandage pressure.

The direction you apply a bandage shouldn’t matter. Bandage the leg in whatever manner is most comfortable for you and achieves the desired effect of consistent covering and light compression. What’s most important is that you apply it with even tension and without wrinkles and ensure it isn’t too tight or too loose. If too tight, the bandage can compress tissues and compromise blood supply. If too loose, it’ll sag and potentially slip down, which can scare a horse into reacting violently and inflicting self-injury.

Once you’ve placed a bandage over a long bone with or without incorporating a joint, place elastic tape (such as Elastikon) around the top and bottom of the bandage. It helps to incorporate a joint above and/or below the bandage to avoid slippage.

“Stacking” is another useful technique for preventing bandage slippage. Take, for example, a carpal (knee) wound: “First place a full bandage (or a standing wrap) from the top of the cannon bone to incorporate the fetlock,” says Denney-Jones. “Then apply the carpal bandage over the wound, and include ample cotton padding on the back of the knee over the accessory carpal bone to protect against rubs or pressure sores. Then connect the carpal bandage directly to the cannon bandage—the secure cannon bandage holds the carpal bandage in place.” You can also use the stacked method on hind limbs to keep bandages from slipping.

For hock injuries, you’ll probably want your veterinarian to bandage these or at least instruct you on the best method. It helps to pad the point of the hock and the Achilles tendon with cotton, then wrap the entire area from gaskin (the area between the stifle and the hock) to below the hock. A stretchy sticky tape like Elastikon has give and elasticity that protect against tissue constriction. Once you’ve encased the hock in bandaging material, be aware that the horse might react to feeling that constriction upon first walking forward. Some raise the bandaged rear leg in protest, hop around without regard to obstacles or people, and are at risk of falling. To prevent this, after placing the hock bandage I immediately but gently back the horse up until he stops reacting to the bandage. This greatly reduces the risk of him falling or kicking or further injuring himself. Ensure there is plenty of room to back a horse, and make sure all people and pets are out of the way.

Bandaging a foot requires a few tricks to keep the bandage from riding up. Denney-Jones prefers to incorporate the entire foot in a bandage to prevent the material from rolling. I have had great success creating a figure-eight ­configuration across the heel bulbs. Then you can apply a hoof boot (with cotton sticking up the sides to keep shavings or dirt from getting in the boot) to further secure the bandage in place. Change the boot daily to remove debris and apply clean cotton. If confinement isn’t necessary for optimal wound healing­—and the boot is designed for turnout—you can turn the horse out wearing the boot.

Signs of Poor Healing

It’s important to look for signs of problems throughout the wound-healing process. “If you (notice) swelling, pus, a bad odor, or feel abnormal heat in the leg, it is appropriate to contact your veterinarian with a phone call and/or by emailing or texting a photograph of the injury,” says Denney-Jones. “Not all correspondence with your vet is going to cost you (a farm call); it’s better to discuss the injury and then schedule an appointment if it seems appropriate for your horse to receive professional care.”

Another sign of a big problem is visible bone. Exposed bone is susceptible to infection, and it is important for granulation tissue to form over the top of the bone as soon as possible. However, excessive amounts of proud flesh covering a wound might obscure your ability to see inside. A wound that continues to produce proud flesh and is not healing usually indicates deeper infection or a bone sequestrum (a dead piece of bone that has separated off the parent bone and lost its blood supply).

“A wound that doesn’t heal after about six weeks should be radiographed (X rayed) to look for a sequestrum that likely requires surgical removal,” says Denney-Jones. Other issues that can deter or delay wound healing include:

• Infection;
• Flies, including fly larvae that create summer sores in certain climates; or
• Foreign bodies such as wood splinters, metal, thorns, or seeds.

Denney-Jones recommends owners in the southeastern U.S. cover horse wounds in late spring, summer, and early fall to shield them from flies. In drier climates it’s still smart to cover wounds during these periods to keep out dirt and insects and prevent tissue from dehydrating.

Take-Home Message

With direction and practice, you can become a wound bandaging wizard. Bandaging is important for creating an environment in which tissue can heal. The main ingredient for successful healing is keeping the wound clean. If you have any doubt about a wound’s seriousness or condition, call your veterinarian. Take a photo, email or text it to your vet, and then keep the wound covered until you can receive professional advice or care.

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Learn steps to safely and successfully add a new horse to an existing herd

We envision our horses living peacefully in wide open rolling pastures, in herds of happy equids that graze together and groom each other’s withers, just like nature intended.

It’s an idyllic image, and equine behaviorists say it’s a fantastic—and realistic—goal. But in practice, when managing herds of sport and leisure horses, it’s not always possible. Some horses suffer the consequences of unfriendly or hostile herdmates—especially when they’re the new kid on the block.

So how do you safely integrate a new horse into an established herd? To accurately answer that question and bring you helpful, reliable advice, we have gone to worldwide experts who speak to the latest scientific knowledge as well as their own real-world experiences.

‘It So Often Goes Wrong’—Introducing New Horses

The fact is horses—like people—don’t always get along with each other at first, says Paula Hitzler, BSc in animal science, farm manager of the Michigan State University Horse Teaching and Research Center (MSUHTRC), in Lansing.

People often add new horses into a pasture with other horses with little to no supervision, expecting them to be compatible. And that, Hitzler says, is the No. 1 mistake they make. 

Kate Fenner, PhD, of the University of Sydney, in Australia, agrees.

“It so often goes wrong,” Fenner says. “People get a new horse, and they throw him into the paddock with the others, and suddenly he’s all beaten up. What we want to really avoid is throwing them out in the paddock and letting them work it out
themselves because, quite often, they don’t do a great job of that.”

Well-planned transitions are a better solution, says Laura Torres Borda, PhD candidate in the Equine Surgery Unit of the University of Veterinary Medicine Vienna’s Department of Companion Animals and Horses, in Austria.

“By thoughtfully introducing new horses, we can minimize these risks and promote smoother integration within the herd, fostering a healthier environment for all group members,” Torres Borda says.

Quarantine for Horses, Homework for You

When buying a new horse, a critical “homework assignment” for new owners is learning about that horse’s social history, Fenner says. If the horse has spent many years stalled and pastured alone, he probably lacks equine social skills—making it harder to integrate into a new herd.

Humans can’t teach this horse-specific social language, Hitzler adds. But without it, your new horse will not understand what other horses are telling him, she says. He’ll need extra time and a gentle horse buddy (more on this in a moment) to teach him the ropes before joining the whole herd.

Once home, be sure to quarantine your new horse for 15 days to ensure he’s not harboring any transmissible pathogens, Fenner says. This is also a great time for him to get used to his new surroundings—which often takes longer than the quarantine period.

Meanwhile, get to know your new horse and take a fresh look at your current herd, she says. This will ensure you know each horse’s personality and the current herd dynamics and establish a helpful baseline for evaluating how the integration is going.

Good Fences Make Good ‘Neigh’-bors

Horse introductions always start with a great fence, our sources say. After the initial quarantine period the new horse should stay alone on one side, while the rest of the herd lives on the other.

At first, use a fence that puts space between the horses, Fenner says. You can use spacer devices, sometimes called standoffs, to hold an electrified line toward the inside of each field. Otherwise, you can space two fences slightly apart to create a sort of “no man’s land” between the barriers. The point is to allow the horses to touch noses but not forelimbs.

A temporary electric fence, placed on either side and about a meter from the main fence, will minimize contact and also stop your horses from getting their feet caught in a wire fence, should one of them strike out at their new neighbor.

Fenner says this allows horses to “get all that striking and vocalizing and that sort of thing over with” while avoiding injury. The fence should be high enough that if horses strike out—as they often do when meeting new horses—their feet won’t get caught in the fence. “That can be really dangerous,” she says.

When everyone appears settled—usually after a few days—switch to a simpler fence, such as a basic two-strand electric fence, which allows for closer contact, she says.

As always, avoid any fence that could cause injuries—especially those with sharp edges like splintered wood or barbed wire.

The ‘Bus Seat Buddy’ and Other Gradual Friendships

Once the herd and new horse have settled on their separate sides of the simple fence, it’s time to find a buddy for the new horse.

Much like people, horses blend better into a group if they can bond with just one or two individuals first. “It’s kind of like when you send your kid to school, and it’s really nice if they meet one or two other kids on the bus before they get there,” Hitzler says. “It seems to help them integrate better when they already have a friend.”

This is usually “much less overwhelming than putting them in together with the
others right away,” Fenner says.

Still, success depends highly on your choice of “bus seat buddy.” For Fenner, it should be “the quietest, most congenial horse” you have in your herd. “That’s the one who seems to get on with everyone and doesn’t really give a hoot about anything else,” she says.

Choose a horse that’s not very aggressive. “I don’t want the new horse being chased off by the one I’m introducing it to,” says Hitzler. “Occasionally, you get nose-to-nose squealing for a little bit, but then they should go on their merry way.”

Don’t confuse low aggression with lowest rank in the hierarchy, though. “Those horses are not socially great,” Fenner explains. “I think they can have a bit of a chip on their shoulders and be a little more testing of newcomers as a result.”

Once the new horse and buddy are grazing peacefully together, our sources say it’s time to choose the next-best buddy from the herd and add that horse to the pair.

One by one, you should add more horses to the new group until the whole herd is present. Importantly, this means bringing the other horses to the new horse and not the contrary, Fenner emphasizes.

For increased safety, it’s best if horses are barefoot during the integration process, Torres Borda says.

Space and Escape

Working out the kinks of a new herd addition safely requires sufficient space. Horses must be able to get away from aggressive members yet respect the personal space of horses that aren’t (yet) their friends.

Such scenes might seem like middle-school bullying, but they’re all part of the natural process of establishing a functioning hierarchy within a group of horses, our sources say.

“Indeed, space availability is very important to obtain a stable group and good cohesion,” Torres Borda says.

“If you’re looking at smaller paddock areas, having rounded corners would be ideal, because horses do need an escape,” Hitzler adds.

If run-in sheds and other buildings aren’t three-sided, ensure there are least two doors so horses can get away from more aggressive individuals, she adds.

3 Phases of Resource Management

Horses can aggressively guard resources—food, water, and shelter, mainly—from herdmates they don’t like but use them to bond with those they do like, says Torres Borda. In fact, she and her fellow researchers recently found that resource sharing and proximity are great ways to gauge how well a horse is melding into a group. “Indeed, only close companions voluntarily eat together in a stable herd,” she says.

Therefore, managing resources wisely across three phases of the integration process can help things go smoothly, our sources say.

Phase 1: Across the fence To encourage friendship-building during separation, place food and water on each side of the fence in spots that bring the horses close enough to share mealtimes without risking conflict. “This may facilitate the integration progress,” Torres Borda says.

Phase 2: Early hours of integration When you first introduce a resident horse into a shared pasture with the new horse, avoid extreme weather days that make shelter valuable. Take out all the resources you can, including hay, feed buckets, and water tubs. Stay out of the field because “all that beautiful positive reinforcement and loving and scratching” that you do makes you a resource as well, Fenner explains.

“Resource guarding will quite often get them into trouble and get them arguing,” she says.

Phase 3: Throughout integration Once the critical first few hours of herd consolidation have passed, reintroduce the resources, but mindfully; space food and water stations sufficiently apart so each horse can eat and drink without “tensions” or “aggressive behaviors,” Torres Borda explains. And ensure there’s sufficient shelter for all horses to enter without crowding, Hitzler adds.

How Long Does It Take? It Depends.

Instead of setting an alert on your calendar, use wise judgment and good observation skills to know when horses are ready for each new step, Fenner says. “It depends entirely on how settled they are,” she explains. “So just wait until you see that they’re getting along.”

Unfriendly behaviors usually subside within a couple of weeks, although it sometimes just takes a matter of days, says Torres Borda. However, it takes much longer than that for all horses to know their place in the overall hierarchy and who their friends are. “A stable integration typically occurs over approximately two months,” she says.

You’ll know your new horse has made a good friend when you see him standing especially close to another horse, she adds, citing her recent research. “Horses form lasting bonds with select individuals—their preferred companions—whom they tolerate within their personal space,” she says.

Importantly, never try to hurry things along or skip steps, Torres Borda warns. “The key to a smooth integration is to make the introduction of a new horse into the established herd as gradual as possible,” she says. “The tendency to rush the process will most likely be detrimental to the horses’ welfare.”

Red Flags, Monitoring, and Intervention

If you respect these guidelines, chances are each subsequent step will go smoothly, Fenner says. But just in case, stay nearby and watch from a short distance for the first 30 minutes, because any serious problems should become apparent by then. Afterward, there’s no need to babysit, she adds; you can leave and then check on everyone again in a few hours.

The next few days involve careful, regular observation and “vigilant monitoring of social interactions and individual well-being,” says Torres Borda. That means noticing who’s being aggressive to whom, and how targeted horses are reacting.

“Keep an eye on your horses, and really know their personalities, and if everyone is settling or not,” Fenner says.

You should also look for horses getting chased away, cornered, or constantly rejected at feed and water sources, she adds. “It’s not uncommon for a horse to be pushed away from the feeders for a couple of days until it finds where it’s comfortable sharing an area with another horse. But if this lingers on, you may have to intervene.”

Compromised nutrition and welfare can change horses’ physical appearance. “You need to watch their weight and their body condition” before and after herd integration, Hitzler says.

Meanwhile, thoroughly inspect horses daily for cuts, scrapes, hair loss, or other signs of injury, she adds.

Any evidence of “excessive and lasting aggression or injuries” merits intervention, Torres Borda says.

Intervention involves moving the target horse to the safe side of the fence and backing up as many steps as necessary to find safe buddies for that horse, says Fenner.

Sometimes, it makes sense to pull both the aggressor and the target out of the herd and safely separate them in adjacent paddocks. “Then eventually you put those two together so they can form a relationship, away from the others, and then go back into the herd,” Fenner explains.

Take-Home Message

Introducing a new horse safely into a herd doesn’t always go smoothly, with pasture injuries a common and repetitive problem. But by following expert advice based on both science and experience, we can improve our chances of success while respecting our horses’ welfare needs.

Age can complicate managing already tricky metabolic diseases in horses

Metabolic diseases, including both insulin dysregulation (ID) and pituitary pars intermedia dysfunction (PPID, previously known as equine Cushing’s disease) occur commonly in horses. Estimates indicate approximately 20% of horses 15 or older have PPID, while the prevalence of horses with ID or a combination of ID/PPID remains unknown.

The most important pathological—involving disease or damage—condition of both ID and PPID horses is laminitis, referred to in this setting as endocrinopathic laminitis or hyperinsulinemia-associated laminitis (HAL). As with other forms of laminitis, horses with HAL suffer extreme pain, lameness, and compromised quality of life.

Rather than delving into the clinical signs and diagnosis of ID and PPID, we’ll move beyond the basics in this article, focusing on best practices for managing aging horses with ID, PPID, or both. The key areas of management we’ll describe include diet and exercise tailored to aged horses, as well as medications. Special consideration also goes to managing older horses with osteoarthritis (OA) and understanding end-of-life care.   

Feeding Aging Metabolic Horses

Without a doubt, diet is the cornerstone of managing metabolic horses to decrease postprandial (after meals) hyperinsulinemia, even if the horse is not overweight.

“It is crucial to limit nonstructural carbohydrates, which are the sugar and starch components of the diet, in horses with ID to control postprandial hyperinsulinemia,” says Erica Macon, MS, PAS, PhD, of the Department of Animal Science at Texas A&M University’s College of Agriculture and Life Sciences, in College Station.

Scientists derived original recommendations of feeding commercialized concentrates and hay with less than 12% NSC from research in healthy horses, and they theorized this level would be safer for horses with metabolic disease. Since then, Macon and other nutritionists have recommended low-NSC hays, decreased pasture access, and ration balancers.

“However, it’s important to recognize that individual horses may have different insulin responses to the same diet,” says Tania Sundra, BSc (Hons), BVMS, MANZCVS (equine medicine), of Avon Ridge Equine Veterinary Services, in Brigadoon, WA, Australia. “Factors such as genetics and the gastrointestinal microbiome likely play a role in this interhorse variability, though this has not been fully elucidated. While some sources suggest a stricter threshold of 10% NSC, the 12% guideline is generally considered appropriate for most horses. Monitoring your horse’s insulin levels and adjusting the diet accordingly remains the best approach to managing horses with ID.”

Macon also points out that “nutritionists are trying to move away from percent-NSC basis. We now recommend that horses with hyperinsulinemia are limited to 0.1-0.15 grams NSC/kilogram body weight (BW) per meal.”

Forage should form the basis of the diet, and horses in good body condition should be offered 2% forage BW. However, if horses need to lose weight this might need to decrease to 1.75% BW or even 1.5% BW.

“But no lower than 1.5% BW, otherwise you jeopardize the integrity of the hindgut,” Macon says. The hindgut refers to the cecum and large colon (or large intestine).

Sundra adds, “Ideally the forage will be split into multiple small meals to mimic a more natural feeding pattern and help reduce the postprandial insulin response by preventing large spikes in insulin that can occur with larger meals.”

Although some producers do have their hay analyzed, the technique might not be ideal or accurate, says Macon. But having a laboratory with an expansive database analyze hay is a crucial step in managing insulin-dysregulated horses, and both she and Sundra recommend it.

“Owners only need to test one batch at a time (i.e., same cutting or load of hay), not each bale,” says Macon.

Lean senior metabolic horses are much more difficult to manage than overweight animals because they need calories to maintain or put on weight, but they still need lower NSC concentrations.

“Most senior horses will experience sarcopenia (progressive loss of skeletal muscle mass), especially those with PPID,” Macon says. “We therefore need to feed quality, bioavailable amino acids. Ration balancers work very well for this.”

Sundra agrees, saying a senior metabolic horse’s diet needs to address both muscle maintenance and safe calorie intake. Her tips include:

• Manufacturers often formulate senior-horse-specific feeds to provide higher-quality protein (including the amino acid lysine) to help combat age-related muscle loss/sarcopenia;
• Calories (energy) should come from safe, low-NSC sources, such as beet pulp without molasses, fats, and oils (e.g., rice bran or flaxseed oil) rather than high-starch grains; and
• Forage should still be the foundation of the diet, with an emphasis on low-NSC hay or a soaked hay to reduce NSC content (be sure to discard the soaking water so the horse doesn’t consume it).

Including Exercise in Treatment

For horses with metabolic issues, especially those that are overweight, exercise should be a fundamental feature of management alongside nutrition. In fact, a combination of diet and exercise resulted in a greater improvement in insulin sensitivity in obese ponies compared to diet restriction alone (Bamford et al., 2019).

According to a survey by Herbst et al. (2024) of 2,700 owners of aged horses, 79% engaged in little structured exercise.

“I was involved in this project and, even though we know exercise is beneficial, the reality is that getting owners onboard is extremely challenging,” says Macon.

The following exercise recommendations come from the European College of Equine Internal Medicine (ECEIM) consensus statement on EMS written by Durham et al. (2019, tinyurl.com/yjnjn4dw):

In nonlaminitic ID horses, minimum recommendations include low-to-moderate-intensity exercise to achieve heart rates of 130 to 170 bpm for more than 30 minutes, more than five times a week;

In previously laminitic horses with recovered and stable hoof lamellae, minimum exercise recommendations involve low-intensity exercise on a soft surface to achieve heart rates of 110 to 150 bpm for more than 30 minutes, more than three times per week, while riders/trainers carefully monitor for signs of lameness.

However, in addition to owner commitment and the laminitic discomfort that limits a horse’s ability to exercise, OA might also contribute.

Arthritic Metabolic Horse Exercise

Among owners caring for aging horses, even without metabolic conditions, OA is a leading concern. In a recent survey of 2,717 U.S. horse owners, researchers found that 30% of horses had veterinarian-diagnosed OA (Herbst et al., 2024). Common methods of managing OA include administering non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone or “Bute” or intermittently giving intra-articular (IA) steroids such as betamethasone.

Medication Effects on EMS Horses

François-René Bertin, DVM, PhD, an associate professor in large animal internal medicine from the Department of Veterinary Clinical Sciences at Purdue University College of Veterinary Medicine, in West Lafayette, Indiana, recently demonstrated that phenylbutazone does not increase insulin secretion in ID horses (Kemp et al., 2024).

Hypothesizing that NSAIDs might increase insulin secretion through prosteglandin E2 (PGE2, principal mediator of inflammation in diseases such as osteoarthritis) inhibition in horses, Bertin et al. administered either phenylbutazone intravenously for nine consecutive days or a saline placebo to nine healthy horses and seven horses diagnosed with ID. Horses then underwent testing to measure circulating insulin and glucose levels and, unlike in humans, insulin concentration decreased.

This suggests that in horses with ID, Bute decreases ID-associated inflammation and improves tissue insulin sensitivity, (crucial for glucose uptake and metabolism) leading to decreased insulin secretion.

“Those effects are rather mild but give us some insight about the role of inflammation in the development of ID,” says Bertin. “These data should not, however, suggest that phenylbutazone is a safe long-term treatment for (horses with) HAL. Instead, phenylbutazone can provide short-term pain relief without increasing insulin in metabolic horses with HAL.” 

Studies of IA corticosteroids do not bring equally good news. Instead, researchers widely report potentially harmful effects of corticosteroids even after a single joint injection. For example, in multiple studies, authors report significant increases in circulating insulin and glucose concentration following a single IA dose of triamcinolone, a commonly administered steroid for managing OA in horses.

Page and colleagues conducted a pilot study to determine the metabolic effects of the corticosteroid betamethasone in five healthy and three ID horses (Page et al., 2025). They injected 9 milligrams of betamethasone into each horse’s front fetlock joint before performing an oral sugar test and measuring adrenocorticotropin—ACTH, a hormone the pituitary gland releases—and cortisol levels (excessive ACTH amplifies cortisol secretion from the adrenals).

They found IA betamethasone had systemic effects on the horses, suppressing both ACTH and cortisol. 

“While it is unknown whether the temporary suppression of ACTH and cortisol is of significant detriment to horses, cortisol is an important hormone in stressful situations, so that raises the potential that these horses may not be able to respond properly to those situations,” Page explains. “There is also the concern that these drugs may cause a temporary immunosuppression, although work to better understand this is ongoing.

“While we were not able to make very many specific conclusions in this preliminary study, we did note that the metabolic effects of betamethasone were similar, albeit shorter lasting and smaller, than triamcinolone,” he adds. “As a result, we again recommended continued caution using corticosteroids in ID and/or laminitis-prone horses.”

Page says the group plans to expand on their work into other IA medications and larger groups of ID horses, given the importance of targeted treatment options for this horse demographic. In the meantime, for those looking for a noncorticosteroid alternative, Page and colleagues demonstrated that autologous protein solution (APS) administered IA did not exert any metabolic effects compared to triamcinolone in healthy horses, suggesting it could be a potential treatment option in ID horses (TheHorse.com/1132877).

Medications to Consider

Pergolide Veterinarians recommend treating PPID horses with pergolide. The 2023 Equine Endocrinology Group reports that clinicians should start with an initial pergolide dose of 2 micrograms/kg (0.5 mg for a 250 kg pony and 1.0 mg for a 500 kg horse) once daily (tinyurl.com/2a9a2wh7).

Practitioners might also consider prescribing cabergoline, a human drug Cabergoline used to treat different types of medical problems that occur when the body produces too much of the hormone prolactin.

Sodium-Glucose Cotransporter-2 Inhibitors (SGLT-2is) When indicated, SGLT-2is might benefit horses with ID. These medications increase urinary excretion of glucose, which in turn decreases the amount of glucose in the circulation. As a result, horses need less insulin to control blood sugar levels. Some published studies support the off-label use of various SLGT-2is, including canagliflozin, ertugliflozin, and velagliflozin, in horses.

“While SGLT-2is can be a valuable tool in managing severe hyperinsulinemia, these medications are typically reserved for cases that have failed to respond to dietary interventions or for severely affected horses where immediate insulin reduction is necessary,” says Sundra. 

She went on to describe four scenarios where she recommends an SGLT2i:

1. Short-term during transition to a low-nonstructural-carbohydrate diet;
2. Emergency use following accidental overconsumption of NSC-rich feed;
3. Preventively prior to corticosteroid administration; and
4. When managing chronic, severe, resistant equine cases.

“Some horses remain persistently hyperinsulinemic despite strict dietary control,” Sundra says. “In these refractory cases, an SGLT2i may be considered for longer-term management to maintain lower insulin levels and reduce the risk of laminitis. However, this should be closely monitored by a veterinarian, as long-term effects and optimal dosing strategies are still under investigation.”

Veterinarians prescribe these medications off label, relying primarily on clinical experiences for evidence of their effectiveness.

“In Australia and the U.K., ertugliflozin is most commonly used in clinical practice,” says Sundra. “The case studies we have published used a dose of 0.05 mg/kg once daily, but some animals might be controlled on lower doses.

“SGLT-2is should be carefully considered within the context of individual risk factors, and their administration should always be part of a comprehensive management plan that prioritizes nutrition, exercise, and overall metabolic health,” she adds.

Combining Pergolide, SGLT-2is Recall that many horses with insulin dysregulation also have PPID and could therefore need treatment for both conditions.

“There are no known interactions between the SGLT-2i ertugliflozin and dopamine agonists like pergolide or extended-release cabergoline,” Sundra explains. “However, it’s worthwhile mentioning that dopamine agonists can sometimes cause a temporary decrease in appetite, so if a horse is already on ertugliflozin and pergolide or extended-release cabergoline is being introduced, I always advise stopping the ertugliflozin for a few days to ensure the horse continues eating to reduce the risk of hyperlipemia (elevated lipid concentrations in the bloodstream).”

Critically Assessing Quality of Life

As one can imagine, it’s not easy managing chronic laminitis in addition to other age-related co-morbidities such as OA. Researchers have reported the prognosis for PPID is poor, with only 50% of horses surviving more than 4.5 years after being diagnosed (Johnston et al., 2025).

As difficult as end-of-life care can be to discuss, preplanning avoids last-minute emergencies and allows your older horses to live their final days with dignity. To successfully navigate the end-of-life phase, owners need to be able to critically assess their horses’ quality of life. In other species various quality-of-life tools are available. In dogs, for example, “The HHHHHMM Scale” (tinyurl.com/3drssxd2) takes the animals’ pain, happiness, mobility, and day-to-day engagement into consideration.

No comparable scale yet exists for horses, but in 2022 Long et al. collected data from 14 published studies on equine welfare that might help owners make informed decisions toward the end of their horses’ lives. They recommend that quality-of-life assessment includes both behavioral parameters to assess the horse’s mental state in addition to the physical state. They further suggest evaluating behavioral and physical parameters over time, stating that assessing quality of life remains an ongoing process, not a single event. 

Ideally, owners partner with their veterinarians to make this delicate decision together, ensuring horses’ best interest is always paramount, regardless of the emotional attachments.

Take-Home Message

Sundra says the greatest challenge in managing aging horses is ensuring a good quality of life while addressing the complexities of aging-related conditions.

“Chronic diseases occurring in older horses, such as OA, PPID, and ID, require proactive management to prevent pain, mobility issues, and laminitis,” she says. 

Nutrition and preventive care play a critical role in managing these diseases in our older horse populations. Early detection and intervention for conditions such as PPID and ID can significantly improve long-term treatment outcomes. “A precision-medicine approach, tailoring care to each horse’s needs, is key, as a one-size-fits-all strategy is unlikely to be effective,” says Sundra. 

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

Q: I often hear the term “essential nutrients” from equine professionals, but I’m not sure what that means or how it affects the way I feed my horse. Can you explain what essential nutrients are and how they should factor into my horse’s diet?

A: Essential nutrients are those we need to provide in a horse’s diet because his body either cannot synthesize them or cannot produce them in adequate amounts. These nutrients support overall health and help prevent deficiencies.

Horses need essential nutrients from six categories: water, carbohydrates, fats, proteins, vitamins, and minerals. Authors of the Nutrient Requirements of Horses, 2007 (NRC) detail the recommended amounts of each essential nutrient to prevent deficiencies, based on the current scientific knowledge.

For example, nutritionists consider vitamin E essential because horses cannot synthesize it in the body, so owners need to supply it in the diet. In contrast, vitamin C does not have a defined dietary requirement because horses can synthesize it from glucose, which experts assume meets their needs.

Following the NRC guidelines will help ensure your horse’s diet meets his nutritional needs. However, it can be confusing and overwhelming to calculate these numbers for your horse’s feed. Luckily, equine nutritionists have already done this work for you.

Nutritionists designed commercial feeds from reputable companies to meet these requirements if fed at the manufacturers’ recommended rates. Ration balancers, performance feeds, and lifestyle feeds can meet your horse’s nutritional requirements when you feed them alongside adequate forage and salt.

Start formulating your horse’s nutrition program by feeding forage at about 2% of his body weight on a dry matter basis. Then choose a fortified feed to cover any nutritional needs the forage doesn’t meet.

The type of concentrate feed you choose depends on your horse’s body condition and workload. For example, a mature horse that readily maintains his weight on forage would be a candidate for a ration balancer. However, a performance horse that is a harder keeper might need a concentrate that also provides supplemental calories. Again, always feed the product at the recommended rate to ensure it meets your horse’s nutrient requirements. If you feed less than the recommended rate, check the label for instructions on combining it with a ration balancer or consult a qualified equine nutritionist to adjust the diet appropriately.

Researchers continue to investigate and define the full range of essential nutrients horses need. For example, horses need amino acids, or the building blocks of protein. There are 21 amino acids, 10 of which are essential. However, researchers have only established a documented requirement for one essential amino acid—lysine. Ideally, we’d have established a requirement for each of the 10 essential amino acids, but that research has yet to be done.

Take-Home Message

To support your horse’s health, feed the recommended amount of each essential nutrient daily as described by the NRC based on the current scientific understanding. Feeding adequate forage, providing salt, and offering a commercial feed at the manufacturer’s recommended rate can effectively meet your horse’s essential nutrient requirements. An equine nutritionist can also help you balance your horse’s diet and be sure his needs are met.

The Kester News Hour at the annual American Association of Equine Practitioners Convention highlight key advancements in equine research worldwide. In 2024’s edition Carrie Finno, DVM, PhD, Dipl. ACVIM, professor of veterinary genetics and the Gregory L. Ferraro Endowed Director of the Center for Equine Health at the University of California, Davis, and Katie Seabaugh, DVM, Dipl. ACVS, ACVSMR, associate professor of equine sports medicine and rehabilitation at Colorado State University, in Fort Collins, shared their top picks from recent studies in their areas of practice interest.

Studying Graying Speed and Melanoma in Horses

Finno began with research by Rubin et al. (2024), in which researchers identified a genetic variation in horses that determines their greying speed and melanoma incidence.

“Graying is caused by a duplication of a 4.6 kb (kilobase, a unit of measurement used to help designate the length of DNA or RNA) intronic sequence in syntaxin 17 (STX17),” said Finno. “If horses have one copy of the variant, then they are not gray. Gray horses with two copies of STX17 gray slowly and have lower rates of melanoma but, if a horse has three copies, then they are the fast-graying horses linked with melanoma.”

For example, if a gray mare has the genes G3/G1 and the gray stallion is G3/G1, then the foal could be G3/G3, meaning he or she will gray very fast and has a higher likelihood of developing melanoma. The results could lead not only to better identification of horses likely to gray early or pass on gray-with-age genes but also to a better understanding of how the mutation affects horses’ health.

Detecting Atrial Fibrillation in Horses

In the second study Finno covered (Vernemmen et al., 2024), researchers described a method for veterinarians to detect atrial fibrillation in horses using an implantable loop recorder (ILR).

The ILRs can be placed under the skin in the left lateral thorax overlying the heart, said Finno. Practitioners use these to detect arrhythmias as a possible cause of collapse, poor performance, or monitor for atrial fibrillation (AF) recurrence in a research setting. The device can now collect information and email the clinician, improving the speed with which AF can be identified.

“Be aware that some false positives can be a result of bradycardia (when the heart beats slower than normal) rather than AF because it is a human product,” said Finno. “And we need to appreciate that AF is likely genetic.”

Identifying A Cause of Neck Pain in Horses

Seabaugh presented a study (Hendersen et al., 2024) in which researchers described the incidence of neck pain without neurologic disease in horses with transposition of the ventral lamina from C6 to C7 of the cervical vertebrae.  

“The ventral lamina is part of the transverse process, and this ventral aspect of C6 can move to the C7 vertebra,” said Seabaugh. “When located on C6, the longus colli muscle attaches to the ventral lamina, which is a cervical flexor. Movement of the transverse process likely affects the biomechanics of the neck.”

In the retrospective study, researchers looked at radiographs taken from 2020 to 2022, including a total of 135 horses. Reasons for radiographs included routine neurologic exam, neck pain, and performance-related behavior changes.

Key findings were:

1. The researchers saw transposition in 20% of the horses that was not significantly associated with a final diagnosis, meaning an equal number of horses with or without the transposition fell into each diagnosis; and
2. Transposition was more common in horses that demonstrated pain during palpation of the neck (31%) than those without pain (18%).

Additionally, 63% (17 out of 27) of the horses with transposition were Warmbloods.

Prevalence of Neck Pathology in Warmblood Horses

Looking at Warmbloods more closely, Seabaugh presented a second study (Sue Dyson et al., 2024) where researchers described the prevalence of C6 and C7 transposition in the breed.

“This study included only Warmbloods: 127 controls and 96 horses with neurologic abnormalities, neck pain or stiffness, or neck-related forelimb lameness,” Seabaugh said. The researchers found 24.2% of horses had C6 and C7 transposition. Horses without neurologic issues (the controls) were more likely to have this variation than those with neurologic abnormalities.

“The conclusion from both studies was that there is no association between C6/7 transposition and neurologic disease, and it is just a variant occurring in up to one-quarter of all horses,” said Seabaugh.

Updated ACVIM EHV Consensus Statement

Finno broke down the updated ACVIM consensus statement for equine herpesvirus (Lunn et al., 2024) for the audience.

Three key takeaways from the new guidelines included:

1. Researchers have seen minimal evidence that the vaccine protects horses against equine herpesvirus-1 infection, but they still recommend vaccinating.
2. Pharmacological treatments have minimal effect (except valacyclovir if administered in advance).
3. In large outbreaks nasal swabbing typically suffices for diagnosing affected horses; however, when abortion occurs on the premises, veterinarians need to test blood samples.

In a study following the herpesvirus outbreak in Valencia, Spain, “Sixty-eight percent of horses with neurologic disease returned to exercise, and over half returned to full performance,” said Finno. “But the less ataxic they were on presentation, the more likely they were to fully recover. If there was urinary and vascular compromise, then they were more likely to be euthanized.”

Spring has officially sprung in Kentucky with flowers in full bloom and the horses off to the races! While we may be excited to get outdoors and enjoy the sunshine after a long winter, the warm weather also draws out other critters … ticks. Often overlooked compared to mosquito-borne pathogens, ticks are capable vectors of several equine diseases and can cause adverse effects ranging from local irritation to acute and chronic disease. Proactive tick management is an essential component of equine preventive care, particularly as many regions continue to report increased numbers of tick bites and changes in tick species distributions.  

In the United States, notable tick-borne diseases affecting horses include:  

• Equine Granulocytic Anaplasmosis (Anaplasma phagocytophilum) – most commonly observed signs of infection include fever, lethargy, limb edema and ataxia. In equines, A. phagocytophilum is most commonly transmitted by the blacklegged tick (Ixodes scapularis) in the Northeast, Midwest and parts of the Southeast, but may be transmissible by the Western blacklegged tick (Ixodes pacificus) on the West Coast.  

• Lyme Disease (Borrelia burgdorferi) – although horses are less susceptible than dogs or humans infection can result in chronic weight loss, shifting lameness, behavioral changes, and neurological signs. This disease can be difficult to diagnose in equines, as a positive blood test indicates exposure to the pathogen but not necessarily current disease status. Lyme Disease is also transmitted by I. scapularis.  

• Equine Piroplasmosis (EP) – caused by Babesia caballi and Theileria equi. This disease is reportable in the mainland U.S., but endemic in Puerto Rico and the U.S. Virgin Islands. Transmission can occur through tick bites (most commonly from Dermacentor or Rhipicephalus spp.), but most U.S. outbreaks or reports of disease are associated with iatrogenic transmission from contaminated equipment during unsanctioned racing events or through illegal importation of infected Quarter Horse racehorses.  

• Tularemia (Francisella tularensis) – a rare tick-borne zoonotic disease in horses, associated with Dermacentor spp. and Amblyomma spp. ticks. This pathogen can be transmitted through bites from fleas and flies and through contaminated water sources, but is most commonly associated with tick bites. While rare in horses, it is of veterinary and public health significance due to its ability to persist in the environment, multiple modes of transmission and zoonotic disease potential.  

• Tick Paralysis and Hypersensitivity – Toxins in tick saliva may cause neuromuscular dysfunction or localized inflammatory responses in sensitive animals.  

Emerging Tick Species: Asian Longhorned Tick  

The Asian longhorned tick (Haemaphysalis longicornis) is an invasive species that has been detected in numerous U.S. states along the East Coast and Appalachian Mountains, including Kentucky, where it has been detected on wildlife, cattle, equines, dogs and people.  

• It reproduces asexually via parthenogenesis, enabling rapid population growth and large infestations, particularly on livestock.  

• This tick has been documented on horses in the U.S., although no confirmed cases of equine disease have been associated with it.  

• Internationally, H. longicornis can transmit pathogens of veterinary and medical concern, causing diseases such as anaplasmosis, babesiosis, ehrlichiosis, theileriosis and rickettsiosis.  

• Its ability to cause anemia and death in cattle raises concern for similar effects in heavily infested horses, particularly if infestations go unnoticed, though such cases have not yet been reported.  

• As horses can develop hypersensitivity reactions to tick and other arthropod bites, even mild infestations of H. longicornis could exacerbate stress, pruritus and allergic dermatitis, affecting welfare and performance even in the absence of pathogen transmission. 

Most Common Equine-Associated Tick Species in the U.S.  

• Amblyomma americanum (lone star tick)  

• Amblyomma maculatum (Gulf Coast tick)  

• Amblyomma mixtum (Cayenne tick)  

• Dermacentor albipictus (winter tick)  

• Dermacentor andersoni (Rocky Mountain wood tick)  

• Dermacentor variabilis (American dog tick)  

• Haemaphysalis longicornis (Asian longhorned tick)  

• Ixodes scapularis (blacklegged tick)  

Integrated Tick Prevention and Property Management  

Most tick species tend to prefer habitats with shade, moisture and vegetation, including wooded edges, brush and tall grasses commonly found on or adjacent to horse properties, or along trail riding locations. To reduce equine tick exposure, there are environmental, behavioral and chemical strategies available to reduce the number of ticks on the property and reduce equine exposure to areas where ticks may be more common. This can include pasture and property management to reduce areas that are more likely to harbor ticks and reduce wildlife from bringing ticks onto the property. Integrated management also includes on-animal prevention strategies to reduce ticks from attaching to animals and removing ticks quickly when they do attach to animals.  

Pasture and Property Management  

• Mow and maintain pastures frequently to reduce habitat more likely to harbor ticks.  

• Create buffer zones between wooded or brushy areas and paddocks.  

• Remove brush, leaf litter and overgrown field margins.  

• Exclude wildlife (e.g., deer, raccoons) via fencing or deterrents to reduce tick introduction and movement of disease-causing pathogens.  

• Control rodents through exclusion and secure feed storage; rodents serve as reservoirs for immature ticks and several tick-borne pathogens.  

On-Horse Prevention  

• Perform daily tick checks, focusing on thin-skinned, less-visible areas such as ears, eyelids, muzzle, chest, belly, mane and tail. Full body tick checks are recommended after equines have been in areas where ticks may be more common, such as after trail rides in brushy habitat.  

• Apply EPA-registered pyrethroid-based sprays labeled for equine use. Reapplication may be needed based on rainfall or sweat exposure and is typically only effective for short-term applications.  

• Fly sheets or insect barriers may provide partial protection from both biting flies and ticks.  

• Avoid off-label or overuse of pesticide products to prevent skin irritation or systemic absorption. Consultation with a veterinarian before application of on-animal chemical products is highly recommended.  

When to Heighten Vigilance  

• After trail rides or turnout in brushy or wooded areas.  

• During peak tick activity months: spring through fall, although milder winters may support year-round activity in parts of the Southeast and South-Central U.S.  

Veterinary Role in Surveillance and Education  

Veterinarians are well-positioned to contribute to equine welfare through owner and caretaker education on tick-borne diseases and bites and preventative approaches for tick and other arthropod-borne diseases and associated conditions. In many states, ticks can be submitted for identification through the state’s Departments of Agriculture, Environmental Health or Public Health Departments, or through state Extension services. In Kentucky, suspected Asian longhorned ticks can be submitted through the University of Kentucky Cooperative Extension Service by bringing them to your county Extension office, mailing them to the Entomology Department through the contact information below or by contacting the Office of the State Veterinarian at statevet@ky.gov.  

For identification of suspected Asian longhorned tick in Kentucky, please preserve specimens in ethanol or hand sanitizer (without additives like aloe), or in a ziplocked bag after freezing specimens (to kill ticks). Mail specimens to University of Kentucky Veterinary Entomologist, Dr. Hannah Tiffin, at the University of Kentucky S-225 Ag Science North Lexington, KY 40546-0091 along with information on date of collection, host animal collected from, county of collection, and follow-up contact information. 

Editor’s note: This is an excerpt from Equine Disease Quarterly, Vol. 34, Issue 1, funded by underwriters at Lloyd’s, London, brokers, and their Kentucky agents. It was written by Hannah Tiffin, PhD, assistant professor at the University of Kentucky, in Lexington.   

Do we underestimate the impact of ill-fitting tack?

Some analogies compare the equine back to a violin. The horse’s spine is the wooden body of the instrument, and the muscles are the strings. When the horse’s muscles and other soft tissues move the spine, the structures must stretch and extend accordingly for the entire instrument—the back—to function. The horse’s ability to engage and use his back depends on well-­developed and healthy musculature. Underutilized, atrophied, or spasmodic or otherwise painful muscles disrupt the animal’s locomotion. Unfortunately, this kind of muscle damage often occurs due to a common, often-overlooked culprit: ill-fitting saddles. In this article we’ll tackle the process of recognizing and addressing saddle fit problems to help you be sure your equine partner has a pleasant experience in the tack.

The Importance of a Saddle That Fits

Imagine running a 5K with sneakers that are too small and tight for your feet, causing blistering pain with every footfall. Or picture a track-and-field athlete attempting to navigate a course of hurdles while wearing tightly buttoned jeans that dig into the skin and cause uncomfortable friction at the seams. These struggles are similar to those horses endure in the hands of well-­intentioned but ill-informed riders—and even trainers. Undoubtedly, pain, lameness, muscle atrophy, and behavioral resistance in the ridden horse can all be linked to an improperly fitting saddle. With so much potential for harm if fitted incorrectly, saddles deserve the attention of the professionals on your horse’s team—­veterinarian, bodyworker, and saddle fitter.

When it’s Time to Call a ­Pro

“It’s crucial to involve a saddle fitter when your horse’s body has changed for any number of reasons,” says Jenna Shipley, of Shipley Equine Services, a certified equine bodyworker and saddle fitter based in Carmel, New York. Like most independent professional saddle fitters, Shipley recommends a routine saddle checkup at least twice a year. She names a few scenarios that might affect this schedule and warrant dialing your saddle fitter’s number:

• Extreme weight gain or loss. This can include significant muscle loss from a period of inactivity, decreased nutrient intake, or even systemic illness.
• Starting (or restarting) a horse under saddle. Commencing training with properly fitted tack is better than fixing problems down the road.
• Rehabbing a horse after a period of stall rest due to injury. Shipley says the shape of the topline will change when transitioning from inactivity back to work and encourages horse owners to have saddle fit evaluated throughout the rehabilitation process.
• A change in riders. “Crooked riders make crooked horses,” says Shipley. Researchers have shown riders who are too large for the saddle, out of balance, or crooked create uneven force distribution across the tack (Bondi et al., 2019). “These unbalanced riders can actually change the quality of their tack, creating unbalanced, asymmetrical saddles,” she says.

Furthermore, ill-fitting saddles can create a “vicious cycle,” our sources say. “Horses with saddle-induced back pain can have the shape of their back change, often dramatically, in a short amount of time, from the associated muscle atrophy,” explains Shipley. “We have to remember how dynamic a horse’s musculoskeletal system is, how much it responds to its environment.”

Erin Contino, MS, DVM, Dipl. ACVSMR, associate professor of equine sports medicine and rehabilitation at Colorado State University, in Fort Collins, echoes these observations: “Whether from saddle fit issues or underlying back pathology (disease or damage), horses with back pain will often ‘turn off’ their stabilizing muscles, causing them to atrophy. Many horses with back pain will appear to have lost muscle mass over their topline rather quickly.”

As a general rule, Shipley recommends more frequent saddle fit checks for horses in a dynamic program—green horses that are still maturing, athletes rehabilitating from an injury, or horses experiencing a variable workload throughout the year—than those in a static program. This latter group is governed by consistency: These horses have a steady workload throughout the year, and their bodies are less likely to change rapidly.

Realistically, many horse owners look for more practical and cost-effective alternatives to having their saddles ­professionally ­evaluated and adjusted as frequently as every couple of months. Researchers’ findings suggest certain saddle pads can in some cases reduce pressure on the back (Kotschwar et al., 2010).

“I do see value in some half pads that come with the ability to have shims added and subtracted, as they can be particularly useful during these times when the horse’s body is changing a lot,” explains Shipley. “The reality is that although corrective saddle pads can temporarily improve the fit in certain cases, they can’t be a permanent solution.” And more padding isn’t necessarily harmless—layering on various pads to correct a gullet or tree that’s already too narrow will only make matters worse, similar to adding thick socks to your tight shoes.

How to Evaluate Saddle Fit

Our sources list eight elements to assess:

1. Saddle balance. The saddle must be balanced from front to back and from side to side to avoid putting excessive pressure on any portion of the horse’s back or shifting with movement. 
   
2. Panel contact. Both panels should make full, even contact with the horse’s back. Full panel contact prevents the saddle from rocking back and forth. It also helps distribute the rider’s weight evenly across the horse’s entire back, ending just before the last vertebrae (typically the 18th thoracic vertebrae—T17 in some horses—which is the point of junction for the last rib). If the panels are flocked with wool, they can be reflocked to address imbalances. Foam panels, on the other hand, do not offer that option.
   
3. Wither clearance. “Lack of wither clearance is one of the most common issues I see in performance horses,” says Shipley. It’s easy to see why a saddle that puts direct pressure on or around the horse’s sensitive, bony withers hinders range of motion and causes pain. A horse whose saddle pinches his withers might be reluctant to move forward and might show behavioral signs of pain such as kicking out and bucking.
   

4. Gullet width. How wide or narrow the gullet is dictates the weight distribution of the rider across both sides of the horse’s back. The width of the horse’s individual spine and musculature at the withers should dictate gullet width. Researchers have confirmed excessive padding can make an otherwise well-fitting gullet too small (Bondi et al., 2019).
   
5. Tree width. “The tree points located at the front of the saddle should mirror the angle of the horse, allowing the shoulders to rotate comfortably,” says Shipley. “If the tree is too narrow, it will restrict shoulder movement and likely cause pain. If the tree is too wide, the entire saddle will be unstable and have excess pressure at the front of the saddle. It may rock or slip from side to side, or the back half of the saddle may twist to one side or the other.” As their names indicate, saddles with adjustable trees can be modified, to some extent, to fit the horse. Traditional saddles—those without the built-in adjustable tree option—need to be replaced if the tree no longer fits the horse.
   
6. Billet alignment. The billets—the leather straps to which the girth connects on both sides of the saddle—should be perpendicular to the ground. Being pulled too far forward or too far back by the girth will alter the fit of the saddle and might also cause unnecessary pressure and movement at the front or back of the saddle. In Western saddles the same concept applies with the cinch strap or latigo.
   
7. Seat size. The pommel of the saddle must be at least 2 inches (or three fingers) behind the back of the scapula, providing enough freedom for the shoulder blades to move backward during extension. In both English and Western disciplines, the saddle panels should not extend farther back than the 18th thoracic vertebrae and last connecting rib into the lumbar spine region. A saddle of improper length, front to back, interferes with the balance of both horse and rider.
   
8. Tree integrity. This last one is easily overlooked. “If you buy a used saddle, or if your horse falls or rolls with the saddle on, have that piece of tack checked by a professional,” says Shipley. “Otherwise, a broken tree could go unnoticed for weeks or even months, causing damage to your horse’s back and risking the rider’s safety. On a related note, if a stirrup catches on something and pulls on the saddle, that stirrup bar can bend, putting sharp and uncomfortable pressure on the horse through the saddle.”

Addressing Back Pain: The Role of Therapeutic Modalities

To break the cycle of saddle-induced pain and dysfunction, rider and trainer must remedy the root cause of the problem—­saddle fit—before any treatments can provide lasting results. “No therapeutic modality can fix poorly fitted tack,” says Shipley. “Massage is just a Band-Aid if the fit is not being simultaneously addressed. From personal experience doing equine bodywork, I’ve worked on many sore backs that would improve by the end of the session, only to be braced, reactive, and sore after the very next ride in the ill-fitting tack.”

That’s not to say therapeutic modalities such as massage and pulsed electromagnetic field therapy (PEMF) don’t have value in detecting and mitigating ongoing problems, our sources say. “Oftentimes it’s actually these practitioners of therapeutic modalities who first discover the subtle signs of ill-fitting tack and can refer the client to a saddle fitter,” says Shipley. “By working on the horse, they can detect cues such as asymmetrical back pain, girth area sensitivity, or subtle changes of the hair over the back.”

Both Shipley and Contino encourage a holistic approach to rehabilitation from saddle-induced back pain. “In most cases the horse has muscle dysfunction all throughout the body as a result of compensating for their painful backs and not using their bodies properly,” Shipley explains.

Contino adds that even once you remove the “nidus” (in this case, a poorly fitted saddle), these back muscles that have switched off as a result of pain don’t switch back on automatically. Thus, the long-term physical consequences of ill-fitting saddles largely depend on what is done to reengage the back muscles. If you don’t act, the horse might end up in a downward spiral where he continues to lose muscle mass and strength. But if you do introduce interventions such as core strengthening exercises, the back muscles can return to normal function and strength, limiting long-term consequences. Shipley goes as far as recommending a full rehabilitation program for horses that have had poor saddle fit for a considerable amount of time. Some severe cases might even require giving the horse time off from riding before starting again in new or properly fitted tack, she says.

Looking Ahead: Long-Term Impact of Poor Saddle Fit

“The majority of horses with poorly fitted saddles have pain, or at least soreness, in the muscles on either side of the withers,” says Contino, naming specifically the spinalis muscle and part of the trapezius muscle. “Fortunately, once the saddle fit issue has been corrected the muscle soreness often resolves. However, in some instances, if a saddle or pad … is actually directly ­contacting the withers, a pressure wound can occur in which case, even when it is healed, scar tissue would remain. Scar tissue is less elastic than normal connective tissue and, thus, there may be limited gliding of the skin over the underlying tissue.”

Take-Home Message

Much like a pair of good shoes, good tack that fits your equine athlete properly makes all the difference in both comfort and performance. Learn to observe and advocate for your animal. “Feel his back regularly, and learn what’s normal for him,” says Shipley. “Reactivity over the back often indicates a tack fit issue.” Many horses are stoic and show no outward, behavioral signs of pain. “But a high pain tolerance does not mean they are not feeling pain,” she says. Attentive examination and early intervention by a professional are the keys to resolving saddle fitting problems before they cause bigger issues.

Researchers continue to learn how the components of a horse’s diet can help battle inflammation

Human nutritionists and doctors often encourage patients to consider diet changes to avoid or reduce inflammation. A list of healthy eating tips from the University of California, Davis, suggests eating more fiber and high-fiber carbohydrates, among other things.¹ Researchers from John Hopkins Medicine and Harvard Health suggest adopting a Mediterranean diet because it is based on omega-3 fatty acids, vitamin C, and fiber-rich foods.^2,3

Increasingly, horse owners want to know if dietary changes can help reduce or avoid inflammation in their horses, too. Researchers continue exploring the link between nutrition and inflammation in equine medicine. Despite progress, gaps remain in understanding how diet influences inflammation—both positively and negatively.

“My big caution to horse owners is not to assume that just because it works in a human that it’s going to work in a horse,” says Sarah H. White-Springer, PhD, associate professor of equine physiology at Texas A&M University, in College Station. “We expect it to be similar because horses are monogastric, and so digestion and absorption that happens before the hindgut, where all the microbes live, should be similar. What we’re finding is sometimes that’s not exactly true.”

That said, a growing body of data, especially related to antioxidant supplements and nutrients such as vitamin E, selenium, and vitamin C, show correlations between nutrition and inflammation. Here we’ll provide a look at what experts know so far.

Understanding Inflammation in Horses

Inflammation is the body’s response to injury, infection, or stress. Jessica Suagee Bedore, PhD, associate professor of practice in the School of Animal Sciences at Virginia Tech, in Blacksburg, says that it’s critical to recognize that inflammation is not always harmful. It’s part of the body’s natural response to stressors such as exercise.

“In normal inflammatory processes, inflammation is important for clearing damaged tissue, and anti-inflammatory processes should take over after inflammation has done its job,” she says. “So, we don’t want anti-inflammation too soon.”

White-Springer agrees some level of inflammatory response plays a necessary role in triggering adaptation. “Simply reducing inflammation may not be the best approach because it could be detrimental to the horse’s ability to adapt to stressors,” she says. “So, we need to be careful about blunting the inflammatory response entirely.”

She says measuring subclinical or cellular-level inflammation in horses presents a major challenge. The difficulty arises because outward signs of inflammation aren’t usually visible without a significant injury.

“Our lab is trying to identify or quantify subclinical inflammation—inflammation that might be happening at the cellular level, but maybe that we can’t see on the outside yet,” White-Springer says. “I think if we can answer ‘How do we define inflammation, before we can see it?’ then we can start to investigate, ‘What are the things that can improve that inflammation or mitigate that inflammation?’”

Ingredients That Tend to Have Anti-Inflammatory Properties

Kathleen Ivester, equine research scientist in the Department of Veterinary Clinical Sciences at Purdue University College of Veterinary Medicine, in West Lafayette, Indiana, says polyunsaturated fatty acids (PUFAs) play a crucial role in managing inflammation. The balance between omega-6 and omega-3 fatty acids significantly influences the body’s ability to regulate inflammation.

“The omega-6 fatty acids are converted arachidonic acid, the precursor to many inflammatory mediators including prostaglandins,” she says. “In contrast, omega-3 fatty acids are converted to molecules that promote the resolution of inflammation. The same pathways use omega-6 and omega-3 PUFAs as starting material, so the balance between the two is very important. Diet determines how much omega-6 and omega-3 PUFAs are present.”

Researchers from Purdue demonstrated that the type, quality, and feeding methods of forage impact respiratory tract inflammation in horses. This occurs both due to variations in dust exposure and nutrition.

“We have found a strong benefit of supplementing DHA (docosahexaenoic acid) or EPA (eicosapentaenoic acid) and DHA together in a few randomized controlled clinical trials,” says Ivester.  “We have been surprised at how quickly we see improvement in coughing and in the amount of inflammation in the lung.”

Suagee Bedore added that omega-3 fatty acids—particularly EPA and DHA—have been studied in horses in disease states beyond respiratory tract inflammation.

“Because these are the precursors of metabolites used in the inflammatory cascade, we know their cellular function in anti-inflammatory processing,” she says. “There are probably at least a dozen other nutraceuticals, including vitamin E, curcumin, Cannabis sativa, and resveratrol. But I encourage each owner to read original research, at least the abstract, to check the dosing and which disease the nutraceutical was tested in.”

Juliet M. Getty, PhD, owner of Getty Equine Nutrition LLC, in Denton, Texas, says “protein quality makes a difference in the horse’s ability to produce and repair tissue as well as keep healthy endocrine and immune systems.”

Ingredients That Tend to Aggravate Inflammation

Researchers have shown diets high in omega-6 fatty acids can promote inflammation. Corn and corn products serve as major sources of omega-6 PUFAs, Ivester says.

“Without a source of omega-3 PUFAs to balance this out, diets rich in corn products will tip the balance toward inflammation  and may create a tendency for chronic inflammatory conditions, including but not limited to asthma,” she explains.

Getty added that excess glucose in the diet can also trigger inflammation. “Insulin is a highly inflammatory hormone,” she says. “Finding forages that offer less than 10% ESC and starch, on a dry matter basis, will help your horse support a healthy weight and avoid the oxidative stress that comes with insulin resistance.”

Getty says excessive production of free radicals and too few antioxidants present to neutralize those free radicals cause oxidative stress. When this imbalance exists, tissues sustain damage. As a result, the cells can no longer behave properly, and disease results.

Equine Gut Health and Inflammation

Anti-inflammatory medications represent one of the biggest risk factors for gastric ulceration in horses. Ivester says a diet that promotes inflammation resolution while minimizing the need for pharmaceutical intervention would likely reduce the risk of gastric ulceration.

She notes that the research she has seen suggests diets deficient in omega-3 and high in omega-6 PUFAs not only predispose a horse to inflammation but also are detrimental to the gut microbial population. This further increases the risk of chronic inflammatory conditions.

Getty added that a horse lacking fiber in his diet could suffer from severe inflammation in the entire digestive tract, including ulcers, leaky gut, fecal water syndrome, and inflammatory bowel disease.

“The diet must be forage-based with supplementation to fill in the nutritional gaps that exist with hay,” she says.

“Concentrates can provide added vitamins/minerals, protein, and fat, but they must be fed according to directions to offer the proper amount of nutrients.”

When White-Springer designs a feeding program for horses, she says she starts with a forage-focused diet paired with turnout because horses graze and, when fed that way, tend to do better. She specializes in performance horses, where energy is the primary nutrient need that increases with exercise training.

“A lot of times people will automatically go to a concentrated grain product to add calories,” she explains. “My favorite product to add is beet pulp because it’s highly digestible for the horse, and it’s a fiber, and horses are naturally made to eat more fibrous foods.”

Also, feeding horses only twice daily, a common practice in many barns, might damage intestinal villi and contribute to leaky gut. Whenever possible, provide free-choice forage, though this might not be suitable for obese horses or those with equine metabolic syndrome. Discuss your horses’ specifics with your veterinarian.

Take-Home Message

Equine nutrition plays a crucial role in managing inflammation, but applying human dietary principles directly to horses can be misleading. Emerging research highlights the importance of balancing omega-3 and omega-6 fatty acids, incorporating antioxidants, and prioritizing a forage-focused diet to support gut health and reduce inflammation. Scientists continue to aim for a more tailored approach to managing equine health in their ongoing research.

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

Q: My horse will be turning 20 soon, and my barnmate told me I need to be more cautious about how I feed him vitamins and minerals to ensure I meet his daily requirements. Will his requirements change as he ages? Are there any specific vitamins he might become deficient in? 

A: Just as a human’s nutritional requirements change as they age, so will your horse’s; however, working with your veterinarian and an equine nutritionist can help you ensure he is getting the nutrition he needs during his senior years. 

Vitamin C can be particularly interesting for senior horses. In a study that looked at physiologic differences between young horses and older horses, researchers found that older horses had lower vitamin C levels overall. Of course, horses are a species, unlike humans or guinea pigs or any other animals, that can actually synthesize their own vitamin C, so we don’t know if horses just can’t produce enough vitamin C, or perhaps they use more of it because it is a pretty powerful antioxidant. This might mean that it’s necessary to supplement vitamin C if you have an older horse. 

Just like if a child ate too many vitamin C orange-flavored vitamins, oversupplying most nutrients, including vitamin C, is not a major concern because these can be excreted through the urine. However, there are some theories that oversupplying some vitamins, such as vitamin C, could inhibit the horse’s innate ability to produce them, making continued supplementation necessary. 

As horses get older, they might also become deficient in vitamin E and require supplementation, especially if they have little pasture available to them. When evaluating your horse’s vitamin E levels, it is important to analyze your horse’s diet. However, you can also ask your veterinarian for bloodwork to ensure that your horse’s vitamin E status is good.

Vitamin E is relatively safe, even in higher doses, but it can potentially prevent the absorption of other nutrients if overfed in excessive quantities. Ultimately, working with an equine nutritionist to regularly evaluate your horse’s diet, and with your veterinarian to test your horse’s blood levels will help ensure that they receive proper nutrition as they age. 

Mares can get a bad rap for recalcitrant estrous behavior, but hormones and tumors could also be at play

Anormal mare should behave just like any other horse. So says Paula Hitzler, longtime farm manager at the Michigan State University Horse Teaching and Research Center, in Lansing.

Over her 35 years at the center, home to one of the nation’s oldest Arabian horse breeding programs, Hitzler has seen herds of as many as 125 horses. When The Horse spoke with Hitzler in early 2024, the herd size was 68. Though just 15 of those horses were broodmares, most of the horses kept at the farm are mares because colts are typically sold after they’re started under saddle.

“In my opinion, (with a) normal mare, you should not know by working with her if she’s a mare or a gelding,” Hitzler says. “She should just be a solid citizen.”

Even in estrus it’s rare for otherwise pleasant, healthy mares to display sour temperament, Hitzler says.

“I don’t think that very many mares are ‘mareish,’ ” Hitzler says. Behaviors such as being grouchy, showing signs of heat around people, or urinating while being groomed—“I don’t see very much of that.”

Rather than ignoring or blowing off grouchy behavior as a normal side effect of heat cycles, Hitzler sees “bad” behavior as a potential warning sign that something has gone awry in the mare’s body; maybe the mare’s hormones are out of whack, or maybe the mare has an ovarian tumor. And, of course, mares can experience other ailments, such as injuries, gastric ulcers, or infections. Authors of a 2023 case series on behavioral disorders in mares with ovarian disorders reported that veterinarians must exclude nonreproductive causes of unwanted behavior and reduced performance, such as urinary tract disorders (vaginitis, pneumovaginitis, cystitis, and urolithiasis) and low-grade musculoskeletal pain. Because owners mentioned poor rideability, vets must also rule out rider factors¹.

What Is ‘Normal’ Behavior for Mares During Estrus?

Healthy breeding-age mares spend 15 to 17 days out-of-heat and five to seven days in heat, spring to fall (some sources say 14 to 16 days). Signs that a mare is in heat include receptivity to a stallion (standing when he’s around, for example), frequent urination, raising the tail, and “winking” the vulva.

Whether you find that behavior annoying or problematic depends partly on your perspective and priorities.

If you’re looking to breed your mare, obvious signs she’s in heat make your job easier—so long as the signs of heat reflect reality. If the mare is showing signs of estrus but is not in heat, then timing insemination or breeding could prove tricky.

While Hitzler’s perspective is that grouchy, sour estrous behavior isn’t super common among healthy mares, there’s long-standing scientific literature that says many horse owners feel otherwise. For people who show or compete their mares, when estrous signs do include being difficult to ride or handle, that can be frustrating.

“I did have one grouchy mare we put on Regu-Mate (altrenogest) while we were riding her just to suppress estrous behavior so she wasn’t so grouchy,” Hitzler says.

The drug keeps mares from coming into heat, and it can be useful during competition season.

Evaluating the Mare

If you’re concerned about mareish behavior, pay attention to the frequency, note it on your calendar, and call your veterinarian.

After assessing behavior, practitioners typically examine the mare’s reproductive tract, via palpation and ultrasound, for any irregularities, checking the ovaries’ appearance, relevant structures during the breeding season, and hormone levels to determine her heat cycle stage.

Trouble Ovulating?

When a mare seems to be in heat for longer than expected, it could be she is having trouble ovulating.

It turned out that one of Hitzler’s few “grouchy” mares that pinned her ears during cinching and was irritated by rider leg pressure was in persistent estrus—basically, the ovarian follicle was still developing and had not released the oocyte.

“Upon evaluation using rectal palpation and ultrasound, a persistent follicle was observed,” Hitzler recalls. “Thankfully, a dose of hCG resolved the issue. Sometimes the persistent follicle will not respond to medications. We were thankful that the mare did not have an ovarian tumor.”           

Ovaries and Tumors

Indeed, ovarian tumors can cause behavioral issues, and vets can confirm these growths with ultrasound or hormone testing.

Removing an ovary when there’s a tumor is an obvious choice. Some owners remove ovaries based on behavioral problems even when a tumor has not yet been confirmed.

In the July 2023 study mentioned above, researchers at the Veterinary Teaching Hospital of the University of Teramo, in Italy, reviewed clinical records of mares with a history of problematic behavior that had one or both ovaries removed. Researchers followed up with the mare owners and found they reported improvement in the horses’ behavior. Researchers noted histological exams later revealed granulosa cell tumors (GCTs) or granulosa teca cell tumors (GTCTs) on most of the removed ovaries.

Complaints from the mares’ owners had involved behavior problems during riding.

“They really don’t appreciate when you just try to ride them,” says Giulia Guerri, DVM, PhD, a specialist in equine medicine and surgery, resident ECVDI (European College of Veterinary Diagnostic Imaging), and a researcher in the Equine Medicine and Surgery Section at the University of Teramo.

Guerri was one of the authors of the study who cited “increased sensitivity at both flanks, general problems when ridden, and unwillingness to engage the hindquarters when ridden” as just a few of the problems common to the mares that had ovaries surgically removed.

When the veterinarians found tumors, “common behaviors were also biting or kicking other horses, kicking humans, bucking at work, pulling away from contact when asked to engage the hindquarters, and unwillingness to engage.”

Keep in mind that affected ovaries can become quite large. Normal ovaries are only a couple of inches in length, but a tumor can make them the size of a soccer ball or bigger.

“You can imagine that it’s also a problem during the riding,” Guerri explains. At that size, the ovaries pose a mechanical issue. “After the removal, you see really quick improvement (in) the behavior.”

Tumors can also disrupt hormones.

“The tumor involves specific cells of the ovary that are hormonally active,” Guerri says. “These cells can overproduce hormones (usually inhibin, testosterone, and anti-Müllerian hormone) leading to hormonal imbalances that cause ‘misbehavior.’ ”

In the case series study Guerri and her co-authors wrote, “The best option to diagnose GCT/GTCTs before surgical removal is a hormonal assay to measure the blood concentration of anti-Müllerian hormone. This is secreted by the granulosa cells in the ovary and has recently gained popularity as a potential biomarker for GCT/GTCTs.”

In an Equine Veterinary Journal study², University of California, Davis, researchers reported they were less likely to attribute bad mareish behavior to hormone problems: “Of the abnormal behaviors, stallionlike behavior was the only one that was found to have significant association with increased concentrations of the tested hormones,” the authors wrote.

UTIs and Kidney Infections

Urinary tract and bladder infections in mares can lead to frequent urination, posturing, and perineal irritation, often mistaken for estrous behaviors. Veterinarians typically examine and then treat affected mares with antibiotics to resolve these infections. 

Ridden Mares vs. Broodmares

Riding or exercising your mare can provide additional opportunities to detect that something’s bothering her. Grooming, tacking up, or riding all potentially involve touching the mare’s flanks. As Guerri points out, that pressure might be unpleasant.

Sport horse mares are common in these studies of estrus, ovaries, hormones, and how they impact mare behavior, she says. Returning a mare to productive under-saddle work is a frequent concern.

For owners of broodmares that exhibit problem behavior, there is hope; in the case series articles the authors reported that mares with just one ovary removed were able to get pregnant.

If you’re no longer riding your mare—whether she’s retired to pasture-puff status or is a broodmare—you’ll have to rely on other methods to detect unusual estrous behavior.

Entering estrus in the winter months would be one clue, Hitzler points out. You can also keep an eye out for how she behaves around geldings. Consider shifting turnout arrangements if your mare is sometimes receptive to geldings on a shared fence line. Horses could get hurt when a mare is considerably less enthused about a male horse’s attentions.

“You have to understand behavior,” Hitzler explains. “You have to understand whether this behavior is going to be dangerous for the horse.”

Reading ear, head, neck, and tail expression can help identify problems, she adds.

Other approaches, such as keeping track of food consumption, body condition score, and herd dynamics, might also provide insight.

Your Mare is Unique      

Mares are individuals. Some are spicy by nature while others are personable and sweet. Familiarize yourself with your mare’s habits and demeanor.

Hitzler recommends watching your mare’s facial expressions for clues about her mood or health.

So many people look at horses’ legs, shoulders, and feet while working with them on the ground.

“Look at their faces,” Hitzler urges. “Their faces tell you an awful lot, whether they’re content, whether they’re worried, whether they’re afraid. And then that also coordinates with the ears and neck height and body posture and tail. So, they all go together. But I think a lot of people forget that there’s a lot of facial expressions that go on with horses.”

Take-Home Message

If your mare is acting sour, there might be a health-related reason. Normal estrous behaviors include receptivity to a stallion, frequent urination, raising the tail, and winking the vulva. When estrous signs include sensitivity on the flanks, poor behavior under saddle, tail swishing, and squealing, you might consider chatting with your veterinarian.

References

1. Straticò. P.; Hattab, J.; Guerri, G.; Carluccio, A.; Bandera, L.; Celani, G.; Marruchella, G.; Varasano, V.; Petrizzi, L. Behavioral Disorders in Mares with Ovarian Disorders, Outcome after Laparoscopic Ovariectomy: A Case Series. Vet Sci. 2023 Jul 25;10(8):483. doi: 10.3390/vetsci10080483. PMID: 37624270; PMCID: PMC10458155.

2. Huggins, L. Norris, J. Conley, A. Dini, P. Abnormal mare behaviour is rarely associated with changes in hormonal markers of granulosa cell tumours: A retrospective study. Equine Vet J. 2023. doi.org/10.1111/evj.13967.

Consider these 8 behaviors that could suggest your horse is struggling to see.

You’re walking peacefully along a quiet trail in the woods with your trusty equine friend when, suddenly, you find yourself clinging to the side of the saddle, with your heart beating out of your chest.

Your horse, meanwhile, stands under you, stiff-backed with ears perked, snorting at a stump.

A stump. A measly, graying, run-of-the-mill stump, the likes of which you and your horse have certainly crossed paths at least a dozen times.

You tell yourself, “That’s it—he’s gone completely berserk.” But over time, you start connecting the dots. You realize this spookiness has taken on a pattern.

Indeed, your steed only seems to spook at objects on his left side, for example, and generally on days and during hours when trees cast dark shadows, contrasting the otherwise general brightness of daylight. And that’s when you start to wonder: Is my horse still seeing okay?

It’s a question horse owners regularly pose to equine vision specialist Nicole Scherrer, BA, DVM, Dipl. ACVO, associate professor of clinical large animal ophthalmology at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center, in Kennett Square.

It’s also a mysterious issue equine ophthalmologist Richard McMullen, Dr. med. vet., Dipl. ACVO/ECVO has been studying in-depth in his role as a senior veterinarian in the equine ophthalmology service at the University of Zurich’s Vetsuisse Faculty, in Switzerland.

“If I had a wish, it would be to look through a horse’s eyes for a day because it’s really difficult to know how much they rely on vision,” he says.

Finding the Behavioral Signs of Vision Loss: a Blind Path?

Certainly, vision problems can affect horses’ behavior, Scherrer says. But the types of behaviors can vary vastly from one individual to another. “I don’t even think I can give an exhaustive list of them,” she explains.

Plus, those behaviors can have multiple causes beyond vision issues, McMullen cautions. “I used to think it was so cut-and-dried: They’re shying, they’re bumping into things, they don’t like going from light to dark,” he says. “But there are all kinds of reasons horses do these things. The more cases I see, the more difficult it is to determine what the signs really mean.” 

So, while our sources say it’s impossible to create a definitive checklist of vision-related behaviors, they’ve shared some hints that might suggest your horse is having vision issues. However, they emphasize this list should in no way serve as a diagnostic resource.

In general, vision problems affect one eye more than the other, adds Scherrer. So, if any of these behaviors occur more on one side than the other, that’s a more convincing sign vision troubles could be at play.

1. Spooking or Refusing.

Arguably, the most common reasons owners seek vision workups for their horses are spooking and refusing obstacles, our sources say.

It’s a reasonable assumption—provided the behavior is a new development, says Scherrer. Growing cataracts, for example, can trigger spooking in previously nonspooking horses, she says. That’s especially true if the horse shies when something or someone approaches from his side, because cataracts can block vision at certain angles. Even so, cataracts in other parts of the eye could also affect forward-facing vision, which might interfere with understanding obstacles, for example.

“It could be anything, like stopping at jumps, or maybe having trouble finding distances, whereas they used to be seeing distances just fine,” she says, adding that some horses with flawed vision even balk at specific colors.

That said, many vision-impaired but experienced show jumpers perform very well, notes McMullen. This success is largely due to their ability to draw on previous training and rely on their riders “to accomplish what they need to accomplish,” he says.

Likewise, it’s important to remember that horses can spook for many reasons, he adds. “We get lots of horses referred for spooking, but when we perform a complete ophthalmic examination, we often find no visual defects or refractive errors—meaning they should be able to process incoming light normally,” he says.

2. Reacting Differently to Bright vs. Dark Conditions.

Horses that react differently to various lighting situations could have vision issues, possibly caused by corpora nigra cysts—“little brown balls” in the iris that can grow into larger cysts, which interfere with normal vision, says Scherrer. In bright light, when the pupils are smaller, the cysts take up more of horses’ field of view. “These horses tend to be worse on a really sunny day or out on the cross-country course versus working indoors,” she says. 

In addition, vision-impaired horses might not want to move from bright to darker areas, or vice versa, says McMullen. They could also be wary about stepping between brighter and darker surfaces.

3. Turning the Head in Unusual or Unexpected Positions.

When a horse has particularly uneven vision between his eyes, he might tilt his head or bend his neck to see better view with the stronger eye. This behavior typically occurs only when there is severe or complete vision loss in one eye, Scherrer says.

Certain pathologies (disease or damage) can also affect specific areas of the eye, affecting the way horses adjust their head and neck positions, she adds. “I had a client horse with a cloudy corneal disease called immune-mediated keratitis, and it was on the bottom half of the cornea,” she recalls. “The horse couldn’t find the carrot during low carrot stretches. But once we treated her and her cornea cleared up, she was able to find the carrot again.”

4. Bumping Into Things.

Horses that don’t see well sometimes bump into fences, poles, people, horses, or objects—and then seem surprised about it, McMullen says.

Bumping behavior appears early in young horses with congenital vision issues such as severe retinal problems or cataracts, he says. It can also occur in older horses with sudden onset of vision problems.

Those with more progressive disease processes—meaning they gradually worsen—are less likely to bump into objects due to their training and performance experience, McMullen explains.

5. Getting ‘Lost’ in a New Pasture or When Separated From a Friend.

Some vision-challenged horses might struggle to maintain rank in the social hierarchy if they can’t see well enough to defend resources such as food and shelter, our sources say. But in general, they adapt smoothly in the pasture.

“The last thing a horse wants to do is draw attention to itself and change its status within the herd,” McMullen says. “So if they become visually compromised, that could be a huge problem for them—and it might be part of the reason they’re so good at adapting and covering up those changes.”

“Their whole drive is to not let anyone see that they have a problem,” Scherrer adds. “They do a really good job of pretending that everything’s okay.”

That all changes, though, if these horses lose familiar elements in their environment. “Maybe they’re moved to a different field, or a friend dies, and then all of a sudden they look like they’ve gone acutely blind,” she says.

That’s also the case with vision-impaired horses moving to a new facility or competing in an unknown venue, McMullen adds.

“When I see these horses come in for evaluation, I usually find chronic changes,” Scherrer continues. “So it’s not something recent—it’s just that they’d been really good at hiding their disabilities up to then.”

But even in new environments, visually impaired horses adapt remarkably well, she adds. Her own pony—whose eye troubles eventually led to surgical removal of both eyes—was galloping in a new field within weeks of surgery. “By the second week, you would never have known that that pony was blind, given how she negotiated around the property,” Scherrer says, adding that the mare appeared to “memorize the location” and depend on her herdmates.

6. Headshaking, Increased Blinking, or Squinting.

Headshaking can have multiple causes, but Scherrer says vision problems are certainly worth considering. Specifically, horses with floating structures in the field of view can find their movement “irritating,” prompting them to shake their heads. That can also be the case with corpa nigra cysts, which can be somewhat mobile, she says.

If the vision issues involve pain, horses might blink more often than usual or seem to “squint”—meaning any downward deviation of the upper eyelashes. “Standing in front of the horse can allow you to easily compare the eyelash angle on one eye to the other,” she says. 

Unlike humans, however, horses rarely have issues with eye focus that lead to squinting or blinking, she adds.

7. Grumpiness, Stubbornness, or Any Recent Behavior Change.

Importantly, behavior problems could reflect vision issues truly upsetting and confusing for the horse, our sources say.

Indeed, horses’ reactions to vision loss can be so broad and varied it’s often impossible to associate specific behaviors with specific vision problems, McMullen says. “We often find really significant lesions during an exam, but they are often not associated with behavioral patterns matching that kind of vision loss,” he explains.

Even so, any abrupt new behavior can be an important clue. “Acute behavior changes are always a good indication to look to see if there’s something going on in the eyes,” he says.

“The biggest thing, especially if they’ve had the horse for a while, is any type of change,” Scherrer seconds. “Most of the time when we find an actual eye problem as the cause of a behavior issue, it’s something that the horse had started doing over the last six months to a year or so.”

Some horses—especially stoic breeds such as stock horses—might simply act a little grumpier or more stubborn than they used to, she explains.

“Every time I see something in the horse’s eye, my job is to ask myself, ‘Okay, do these clinical signs meet what I’m seeing in the eye?’” she says. “If there’s any question of a behavior change, it’s just a good idea to get an eye exam.”

Owners can request basic exams from their treating veterinarians during regular checkups or get a specialist referral for more advanced testing. “It’s always worthwhile to mention these things to your vet,” she says.

McMullen agrees. “It’s fairly easy to thoroughly look at the eyes,” he says. “And then if there are no findings, you can start looking for other issues that might explain the problem.”

8. No Unusual Behavior at All.

Because horses have evolved to hide their weaknesses from predators and herdmates, many show no signs of vision loss at all, says Scherrer.

“There’s not necessarily a red flag that goes up for these animals,” McMullen says. “They just tend to adjust really well and accommodate for vision loss—often to the point where they’re completely blind in one or both eyes, and nobody knows it.”

“I’ve even seen horses come in to the clinic who are close to blindness, with disease that’s clearly been going on for years, and their—very good—owners have never even seen them squint,” adds Scherrer, who in a recent study of more than 500 horses found that well-meaning owners frequently noticed no signs whatsoever of minor cataracts.

“It can be really hard to interpret when you have a tricky horse like that,” she says.

Take-Home Message

Horses can cope remarkably well with vision issues—even extreme cases involving blindness—making it difficult for owners to pick up on behavioral signs that their horses are struggling to see well. Still, careful observation can sometimes pick on possible signs meriting a vision workup, at least to rule out sight as a cause. For optimal equine health and welfare, our sources recommend having your veterinarian investigate any new behavioral problems in horses for vision and other health issues, our sources say.

This article is from the Older Horse 2025 issue of The Horse: Your Guide to Equine Health Care. We at The Horse work to provide you with the latest and most reliable news and information on equine health, care, management, and welfare through our magazine and TheHorse.com. Your subscription helps The Horse continue to offer this vital resource to horse owners of all breeds, disciplines, and experience levels. To access current issues included in your subscription, please sign in to the Apple or Google apps OR click here for the desktop version.

Joint pain and osteoarthritis (OA) represent one of the leading causes of performance loss in equine athletes, affecting around 60% of the overall population. Chronic inflammation may cause permanent changes in joint function, leading to long-term pain, swelling and decreased range of motion, among other debilitating symptoms.  

Many of the current OA treatments are management tools that prolong function, generally without modifying OA progression. The most common treatments include non-steroidal anti-inflammatory drugs (NSAIDs) and oral joint supplements that target cartilage repair or protective pathways, as well as joint injections with corticosteroids or newer orthobiologics, both of which are anti-inflammatory. Unfortunately, many of these treatments are associated with other adverse effects, especially when used long-term. 

Several novel treatments to reduce joint inflammation with minimal side effects have been proposed within the scientific community. One such treatment is cannabidiol (CBD), a non-psychoactive chemical compound found in Cannabis sativa (colloquially known as hemp). CBD is known to target the endocannabinoid system, a complex network of several biological systems that affects many physiological processes, including but not limited to, pain perception, appetite, mood, learning and immune function. Within the context of OA, CBD has been found to inhibit the production of substances that increase inflammation, decrease sensitivity of pain-associated receptors and modulate an overactive immune system. Anecdotally, many people claim the benefits of CBD, but more research is required to accurately quantify and qualify its potential benefits and risks. This is especially true within the equine community.  

Our work in the Page Laboratory is interested in understanding the potential anti-inflammatory effects of CBD in joints via the implementation of a three-phase project. We aim to improve a chemically induced joint inflammation model such that it will be repeatable and reversible, while still accurately mimicking the body’s physical and biochemical response to inflammation.  

Phase one involves refining the dosage of a proinflammatory compound which will be injected into one knee (carpal) joint, inducing temporary inflammation. Defining an appropriate dosage protocol and taking note of individual horse variability is an important step for developing a reliable experimental procedure.  

Following phase one, the aim of phase two is to identify an appropriate CBD formulation for oral administration. Due to its chemical composition, CBD is not well absorbed by the equine GI tract, with a bioavailability around 10% (e.g. horses will only absorb about 10% of the CBD administered to them). Previous research has found what a drug is dissolved in can make a large difference in systemic CBD levels, and the most effective candidates are usually composed of fats, such as sesame or canola oil. An optimized formulation is necessary to both maximize therapeutic benefit while keeping palatability in mind for horses.  

In phase three, we will combine the findings from the first two phases and analyze the effects of CBD on the drug-induced inflammatory response. A control group will receive no CBD, and the differences between the treated and untreated group will be evaluated. Horses will be evaluated for several parameters, including the presence of biomarkers associated with inflammation both within the joint and systemically throughout the body. The mild lameness that is induced will be quantified via an objective evaluation system that can better detect the subtleties of gait asymmetries when compared to the human eye.  

While other researchers have shown that CBD represents an exciting prospect for the treatment of chronic joint pain, our research should provide additional information on its efficacy for the horse. Our findings may find applications for human medicine given the mechanisms of OA and joint pain in humans often mimic those seen in horses, which is important given that approximately 45% of people will develop some form of OA within their lifetimes. In the end, we hope to provide a better research model for joint inflammation while simultaneously evaluating CBD as a way to manage joint pain in horses. 

Editor’s note: This is an excerpt from Equine Disease Quarterly, Vol. 34, Issue 1, funded by underwriters at Lloyd’s, London, brokers, and their Kentucky agents. It was written by Jenna McPeek, PhD Graduate Student at the University of Kentucky’s Gluck Equine Research Center, in Lexington and Allen Page, DVM, PhD, assistant professor and faculty advisor at the Gluck Equine Research Center. 

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Q. This spring, I moved my horse to a new barn with grass turnout. My horse hasn’t been on pasture since I got him, and I’m unsure how to make this transition. I know it needs to be gradual, but how gradual, and how do I make it work?

A. I’m sure your horse will appreciate the opportunity to be turned out and have pasture access. But you are correct: Sudden dietary changes, whether it’s the introduction of grain, a hay change, or a move to pasture, can lead to colic and laminitis if done abruptly, whereas a gradual transition allows the digestive tract to adapt. The types and amounts of enzymes the horse’s digestive system secretes are diet-specific. This is also true of the bacteria composing the horse’s hindgut microbiome.

When equine diets change suddenly, feed components that should be digested and absorbed in the small intestine might not be. They might instead reach the hindgut, disrupting the microbiome microbial population. This can result in gas production, hindgut pH reductions (becoming more acidic), as well as die-offs of certain bacterial populations, causing toxin release. All of this can contribute to colic and laminitis.

Early spring pasture contains a lot of moisture, protein, and nonstructural carbohydrates (NSC). NSC includes sugar and starch, as well as more complex fructan sugars. High-NSC diets have two problems:

1. A sudden transition to a diet high in NSC can cause the hindgut disruption already mentioned, because sugar and starch that should be removed in the small intestine are not; and
2. For horses with metabolic issues such as insulin dysregulation and equine metabolic syndrome, NSCs can induce laminitis and founder.

To minimize hindgut disruption, a slow introduction to pasture is necessary, especially for sensitive horses with metabolic conditions. Understanding that these individuals might not be good candidates for any pasture is important. Before you embark on this project, make sure your horse is a good candidate for pasture.

If the barn manager expects pasture to provide real nutritional benefits, fields must be well-established before introducing horses. Putting horses on new pasture too early and before the plants are well-established can be tempting. Wait until the pasture has at least 6 inches of grass before grazing. A safe rule of thumb is that the bottom 4 inches always belong to the plant. If pastures are grazed below that height, you start to rob the plant of its ability to maintain itself, and ultimately your pastures will become overgrazed and plants will die, leaving bare patches and opportunity for weeds to take hold.

Assuming you have the minimum 6 inches of growth, introduce your horse to the pasture initially for just 15 minutes. This might require hand-grazing, because not all horses are going to want to come back inside after only 15 minutes on such a delicacy as spring grass! Then increase the grazing time by about 15 minutes every day until your horse is grazing for about four hours total. Stay at four hours per day for at least a week before granting unlimited access.

Clearly this process is labor-intensive, so it can be helpful to get creative about how you pull it off. The initial 15-30-minute periods can be fairly easily achieved before or after a ride. Allowing 15 minutes before a ride is a great way to get some forage in the stomach. If time is short, do your grooming while your horse grazes, or just hang out and enjoy his company. Then add some time after your ride as a reward. Schedule grazing so longer turnout periods happen on weekends or when you have more time. Ask a friend at the barn to help you out. With some teamwork and creativity, you can transition your horse to pasture safely.

Know when your horse might need one of these important vaccines

Vaccination serves as a core component of equine preventive medicine that can help keep your horse and others safe from dangerous and potentially deadly diseases. Ideally, equine veterinarians administer vaccines early in the year to prepare horses’ immune systems for the coming months when they will likely have the most exposure to some potentially infectious pathogens.

Core vaccines are a necessary part of all horses’ yearly wellness plans with their veterinarians. Regardless of your horse’s activity level, housing, or use, the American Veterinary Medical Association (AVMA) and American Association of Equine Practitioners (AAEP) recommend vaccinating horses annually against diseases that have the potential to affect public (horse and human) health, must be vaccinated against by law, or can cause severe disease or death. These include rabies, tetanus, West Nile virus, and Eastern and Western equine encephalomyelitis (EEE and WEE).

“Core (equine) vaccines are those vaccines that are recommended for all horses, at least annually,” says Elizabeth Davis, DVM, PhD, Dipl. ACVIM, professor and associate dean of clinical programs at Kansas State University’s College of Veterinary Medicine, in Manhattan. “These are diseases that we should recognize that a horse could contract while standing in a pasture, and they are typically diseases that if infected, will be likely to result in serious if not life-threatening and possibly zoonotic (contagious to humans, in the case of rabies) disease.”

Veterinarians administer risk-based vaccines, however, based on a horse’s potential to contract certain diseases, after the owner and veterinarian perform a risk-benefit analysis. Risk-based vaccine plans can vary regionally and should be tailored to the individual horse or farm. When managing a group of horses, combining meticulous biosecurity practices with a strict vaccination protocol can help reduce disease risk.

Risk-Based Vaccines for Horses

Most often, horse owners and their veterinarians determine what risk-based vaccines, if any, a horse could benefit from based on his location, workload, frequency of travel, and resident herd status (i.e., how much the horses leave the farm and commingle with others). The AAEP lists the available risk-based vaccines as:

• Anthrax Horses can contract this serious, septicemic (caused by the spread of bacteria and their toxins in the bloodstream) disease through inhalation, contamination of a wound, ingestion, or mechanical transmission by blood-sucking insects. Horses in geographic locations with alkaline soil are at the highest risk because this environment supports Bacillus anthracis (the causative bacterium) spore survival. Anthrax carries a high mortality rate and can be transmitted between animals of different species.
  
• Equine influenza is the most common respiratory disease in horses and is highly contagious. The virus can spread rapidly through aerosolized droplets distributed when infected horses cough and clear their airways. The most common clinical signs include coughing and abnormal respiratory sounds but also fever, edema, and enlarged lymph nodes.
  
• Botulism This is the most potent known biological toxin, produced by the bacterium Clostridium botulinum. It causes neurologic clinical signs beginning with weakness and quickly progressing to paralysis and often death. The bacterium can be found in decaying animal carcasses or plant material, and horses contract it by inadvertently ingesting it while grazing or eating hay. 
  
• Leptospirosis Infected animals, including wildlife, spread the causative bacteria, Leptospira, through urine and other bodily fluids. Horses can be exposed via open wounds or the mucous membranes, most commonly via water or soil. Clinical signs can include uveitis (ocular inflammation), placentitis or abortion in pregnant mares, or acute renal failure.
  
• Potomac horse fever While this infection most commonly occurs in horses in the eastern United States residing near the Potomac River, cases have been reported worldwide. Horses are most likely to be infected with the causative bacterium, Neorickettsia risticii, between late spring and early fall. N. risticii has a complex life cycle, first infecting parasites of freshwater snails, which the snails release when the water is warm, then infecting larval stages of aquatic insects such as caddisflies, mayflies, damselflies, dragonflies, and stoneflies. These aquatic flies thrive abundantly during specific times of the year and can serve as a reservoir for potential infection during the summer and fall months; typically, horses ingest the flies after they’re attracted to lights in the barn and fall into horses’ feed buckets and hay, or they can ingest them in water. Clinical signs vary but can include diarrhea, fever, mild/moderate colic, and acute laminitis.
  
• Snakebite In areas where venomous snakes such as rattlesnakes and copperheads are abundant, horses have a higher risk of getting bitten, which can lead to death if not treated immediately. Clinical signs can vary based on the type of snake but typically include pain and swelling at the site of the bite. After horses have recovered from snakebite, veterinarians typically monitor them for heart failure or kidney damage, which can occur in the weeks following the bite.
  
• Strangles, caused by the bacterium Streptococcus equi subspecies equi, most commonly infects young horses. Some infected horses might become carriers for an extended time, meaning they can shed S. equi for months or years. This disease is highly transmissible through both direct (i.e., nose to nose contact between horses) and indirect (i.e., a horse drinking from a water bucket that an infected horse used) contact between horses. Infected horses typically exhibit clinical signs such as fever and nasal discharge or pus draining from ruptured lymph nodes around the throat.
  
• Rotavirus This viral infection is spread through the fecal-oral route and is a common cause of illness and death in foals, though it can be largely prevented by vaccinating the dam during pregnancy. Infected foals typically have diarrhea, are lethargic, and will not eat. Although a vaccine for foals exists, there is no published research showing evidence that the vaccine can provide them significant protection.
  
• Equine viral arteritis While typically not life-threatening to adult horses, equine arteritis virus is spread through respiratory secretions in close quarters (i.e., horses stabled near one another), fomites (brushes, humans, etc.), and breeding. Equine viral arteritis can cause abortion in mares, death in young foals, and stallions typically become lifelong carriers. Clinical signs of equine viral arteritis can vary greatly from fever and depression to localized swelling of the limbs (especially hind limbs), scrotum or mammary glands, and underside of the abdomen.
  
• Equine herpesvirus-1 and -4 are most common in horses that commingle with horses from other farms. Both are spread by direct and indirect contact and in many cases establish latent (hidden) infection in horses that then become asymptomatic carriers. Clinical signs of EHV-1 include respiratory disease, abortion, and neurologic defects, while EHV-4 typically causes respiratory disease.
  
• Venezuelan equine encephalomyelitis Horses living in Southern Texas, California, Louisiana, Mississippi, Alabama, and the west coast of Florida have the highest risk of contracting this disease, which is most often seen in Central and South America. This virus is also typically transmitted through mosquitoes. Venezuelan equine encephalomyelitis can cause fever, depression, paralysis, gait abnormalities, and seizures, but the prognosis depends upon the subtype of the virus.

Assessing Your Horse’s Risk

“It is important to make a risk-based decision to understand what is best for the individual horse and the population in which it lives,” says Noah Cohen, VMD, MPH, PhD, Dipl. ACVIM, professor of equine internal medicine, Patsy Link professor of equine research, and associate department head for research and graduate studies in the Department of Clinical Sciences at Texas A&M University’s School of Veterinary Medicine and Biomedical Sciences, in College Station. Not all risk-based vaccines are necessary for every horse, and some might be harmful to certain groups of horses, he adds.

Practitioners might recommend vaccinating horses based on the resident farm population’s risk. An older horse that stays on the farm could have a decreased risk of developing some diseases, but his veterinarian might recommend vaccinating him because young show horses also live on the property.

“Vaccinating the older horse might strengthen herd immunity even if it has little impact for the individual horse,” says Cohen. “Risk-based vaccination should be considered case-by-case (where the case might be a horse, a herd, or both) and there is subjectivity in this decision-making process. For example, a veterinarian might recommend that horses be vaccinated for strangles at a farm with a history of this disease, but not for other horses living in settings where the disease is considered low risk. Another veterinarian might say vaccinating all horses for strangles would reduce the burden of disease for all horses.”

Practitioners often decide which risk-based vaccines a horse should receive based on geographic location, likelihood of exposure, and the horse’s use, adds Davis. “Working directly with a licensed veterinarian is the best way to establish a protocol that is appropriate for a specific horse or situation,” she says. The AAEP consistently collaborates with researchers to develop and publish current recommendations for equine veterinarians and owners to access.

Horses that travel frequently, are exposed to horses from other farms, and are in stressful situations such as horse shows are more likely to develop respiratory disease, notes Davis. “Intense exercise and long-distance travel have been shown to reduce immune function when combined with exposure to other horses that may be shedding pathogens,” she says.

For example, show horses that stable near horses from other farms at competitions or travel with strange horses to and from shows might be more likely to contract EHV-1 and/or -4 than horses that do not have contact with others; therefore, it is important to maintain vaccine protocols as outlined by sport governing bodies such as US Equestrian. “In most instances, show regulations require proof of vaccination against EIV/EHV-1/4 at least every six months,” says Davis. “These vaccines must be maintained on a regular basis and must be administered by a licensed veterinarian.”

Common Risk-Based Vaccine Misconceptions

“A myth that is sometimes shared is that horses maintained on a farm setting or used for breeding are not at risk for disease other than those included with core vaccines,” says Davis. “It is important to recognize that horses leaving and returning to a property can potentially pose risk to other residents.” Horses that live close to others, especially those that share a fence line with horses from another farm, are also at an increased risk of contracting disease even if it might not appear that way, she adds.

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“The risks posed by vaccines have been the subject of much misinformation in both human and veterinary medicine,” says Cohen. “There is little doubt that the benefits of vaccines vastly outweigh the risks. As an equine veterinarian, I hate to think where we would be without vaccines for tetanus, West Nile virus, or rabies.”

Vaccines should always be given to otherwise healthy horses to minimize the risk of adverse reactions.

“In the rare circumstances when an adverse reaction occurs from a vaccine in a healthy horse, it is perceived as more harmful than when an adverse reaction occurs from using a medication used to treat an illness,” Cohen adds. “Preventing disease is a much more effective way of controlling disease than treating cases, but curing an animal of disease is often more compelling to horse owners than preventing disease in a healthy horse.”

Even if a horse develops a disease shortly after vaccination, it’s important to understand it might be coincidental; while adverse reactions do occur, they are much rarer than coincidental events, says Cohen. They are also often—but not always—relatively minor. “The diseases prevented are more serious than the most commonly reported adverse reactions such as swelling or soreness at the vaccine site,” he says. “The USDA’s Center for Veterinary Biologics that licenses vaccines for veterinary medicine has always set a high bar for safety of vaccines, and my limited experience has been that companies that manufacture vaccines consider (product) safety to be just as important as efficacy.”

Take-Home Message

Work closely with your veterinarian to develop a risk-based vaccine plan. Evaluate needs of the individual horse, the herd in which he lives, geographic location, age, and use before determining necessary vaccines. Preventing disease is one of the best ways to improve equine health and welfare. “I think people forget how valuable vaccines are for equine health,” says Cohen. “Failure to vaccinate horses appropriately increases risks for the individual horse, the horses in its population, and—for some diseases like rabies—human health as well.”

Respiratory health directly affects how well a horse can perform, and viral infections in the lungs or airways can seriously interfere with a sport horse’s abilities. Scientists have long known that acute respiratory infections reduce equine performance, but the impact of subclinical (inapparent) viral infections remains less clear, said Thibault Frippiat, DVM, Dipl. ECVSMR, of the University of Liege’s Faculty of Veterinary Medicine, in Belgium. In a recent literature review he and his coauthors, including Dominique-Marie Votion, DVM, Dipl. ECVSMR, evaluated the prevalence of respiratory viruses, how they affected horses clinically, and management strategies.

The Most Common Respiratory Viruses Found in Sport Horses

The research team pointed out the high prevalence of respiratory viruses in both clinically healthy horses and horses exhibiting clinical signs of respiratory illness. When analyzing data from studies that collectively included over 45,000 horses, they found that:

• Equid gammaherpesviruses (EHV-2 and EHV-5) were extremely prevalent, detected in about one-third of all horses, regardless of health status.
• Equid alphaherpesvirus-4 (EHV-4) and equine influenza virus (EIV) were significantly more common in horses with acute respiratory disease than clinically healthy animals.
• Equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), and equine rhinitis A virus (ERAV) were rarely detected in either healthy horses or those showing clinical signs of illness.
• Equine rhinitis B virus (ERBV) was frequently found in horses displaying respiratory illness and might contribute to coinfections with other pathogens.

So while certain viruses lead to clinical disease, others might cause only subclinical infections. These silent infections could contribute to airway inflammation and reduced respiratory efficiency in sport horses, the researchers said, potentially impairing performance without manifesting as signs of illness.

What Does This Mean for Veterinarians and Horse Owners?

For practitioners and horse owners, these results highlight the importance of biosecurity efforts at equine events. Events pose a heightened risk for viral transmission because large groups of horses from different farms congregate in one location, said Frippiat. For certain diseases vaccination remains a cornerstone of prevention, helping mitigate clinical severity and viral spread.

Horse owners should remember that even without visible signs of illness, certain viruses can still hinder a horse’s ability to train or compete. And when horses do show clinical signs, such as fever, coughing, nasal discharge, or other signs of illness such as poor performance, owners need to consult their veterinarians, Frippiat added. Subtle signs of poor performance due to respiratory disease might include tiring easily or having poor results in the show ring (i.e., a show jumper knocking down more rails than normal).

Future Respiratory Research in Horses

While the researchers consolidated existing knowledge, they also highlighted gaps that call for further investigation, said Frippiat. He noted that researchers should further examine how subclinical viral infections affect performance limitations in sport horses.

Advancements in rapid on-site diagnostic tools, such as PCR-based systems, will enhance early viral detection and containment efforts. These systems continue to emerge, he said, but veterinarians need to validate them scientifically before putting them into practice.

Take-Home Message

Respiratory viruses pose ongoing challenges for equine athletes, with potential effects ranging from acute illness to subtle declines in performance. Through strategic vaccination, enhanced biosecurity, and improved diagnostics, veterinarians and horse owners can work together to mitigate these threats and safeguard the health, welfare, and performance of sport horses.

The study, “Respiratory viruses affecting health and performance in equine athletes,” appeared in Virology in December 2024.

Professional human athletes experience strain from frequent, rigorous training and performance. They use various complementary therapies to accelerate their bodies’ natural healing process and ease the discomfort they experience so it doesn’t interrupt their performance. Equine athletes might also benefit from a variety of integrative therapies to help them feel and perform their best.

A significant advantage to using complementary therapies is that they are drug-free and most are allowed during competitions. Electroacupuncture, shock wave therapy, Class IV laser therapy, and cryotherapy are an exception because they are not permitted during FEI-sanctioned events. (Always check the rules governing your competition).

While many complementary therapies can be useful and incorporated into a horse’s wellness program, Tracy Turner, DVM, MS, Dipl. ACVS, ACVSMR, founder of Turner Equine Sports Medicine and Surgery, in Stillwater, Minnesota, says he considers the cost/benefit ratio when deciding which to recommend to a client.

“What does it cost to use it?” he asks. “How much benefit will the horse get? That changes based on the scenario and part of the decisions made by the horse’s health-care team, including the veterinarian, horse owner, and trainer.”

He adds that knowing the goal for using complementary therapies is also critical. If you’re trying to help the horse achieve relaxation (which has its benefits), that’s one thing, but if it is to heal an injury, these therapies on their own will not achieve the desired outcome.

“It’s important to have your veterinarian do a whole-horse evaluation,” he says. “I firmly believe there’s no such thing as a single injury. Diagnosing the underlying issues is essential to knowing how the horse might be compensating in other areas (and) to decide what the horse needs, and fitness comes into the equation, too.”

Picking a modality for your horse and your discipline can feel as overwhelming as restaurant menus with too many choices. Here’s a selection of popular treatments for keeping performance horses feeling their best. Use this article to start a conversation with your veterinarian about options that make the most sense for your horse.

Acupuncture

“Acupuncture is a useful, time-tested modality that has a lot of science and thousands of years of use,” says Andris J. Kaneps, DVM, PhD, Dipl. ACVS, ACVSMR. He owns Kaneps Equine Sports Medicine and Surgery LLC, in Beverly, Massachusetts. More of that science appears in the human literature than in equine studies, however. “It’s gradually becoming more widely recognized as a valid treatment in horses,” he adds. (Read about acupuncture and a review of existing research at TheHorse.com/181626.)

“It has very valid support scientifically and anecdotally,” he says. “A key difference between acupuncture and what we call Western veterinary medicine is that the approach is completely different.”

For example, as a Western-trained veterinarian, he palpates for swelling or increased joint fluid, looks for pain with hoof testers, and performs a lameness evaluation for signs of discomfort. In Chinese medicine those factors are important, but practitioners also evaluate the sensitivity of acupoints throughout the body, assess tongue color and moisture, and examine other factors that aren’t in the normal diagnostic approach for Western medicine, he explains.

Kaneps especially likes acupuncture for horses with back pain because of the equine research that supports its use for such cases, and he has seen multiple horses experience significant improvements after treatment.

“As with all complementary therapies, this does not mean I just treat a horse with acupuncture,” he says. “I may use some Western modalities as well as other complementary techniques to reduce back pain in a horse. Using one alone may not do it, but using several together can improve the outcome.”

Spinal Manipulative Therapy

Inflammation of the nerves and other tissues surrounding joints, especially in the spine, can lead to pain and reduced function, especially when the joints are stiff or immobile. Spinal manipulation (described at TheHorse.com/113280) could help restore the range of motion.

“Chiropractic adjustments keep the horse limber and moving to prevent areas of fixation through the neck, back, pelvis, etc.,” says Ed Boldt, DVM, owner of Performance Horse Complementary Medicine, PLLC, in Fort Collins, Colorado. “Like human athletes, when (horses) are in better shape, they are less likely to have an injury.”

In Boldt’s opinion, horses that are not performing optimally are candidates for spinal manipulative therapy. He uses the example of a barrel horse running to the wall (where the horse runs past the barrel and doesn’t slow down to turn) or going flat (leaning on his front end) around the barrel.

A horse that is three-legged lame is not one that would benefit from chiropractic therapy, he says. “Those horses need a diagnosis and treatment plan, and then integrative therapies might be added to help healing,” he explains.

Boldt also believes veterinarians trained in chiropractic care should make the adjustments. Some states allow chiropractors licensed to work on humans to have animals as patients after completing approved continuing education.

“To me, it’s important the vet is involved either doing the treatment or at least approving of the treatment,” he says.

Chiropractic care without an equine practitioner’s examination might worsen a situation. Boldt remembers being called to examine a horse treated by a nonveterinarian, and the horse was getting sorer rather than improving. By watching the horse move and using hoof testers, Boldt identified the horse had an abscess.

In another case an older horse had fallen on an icy hill and injured his neck. The owner brought it to Boldt, who refused to provide an adjustment without radiographs.

“Thankfully, I insisted,” he says. “The horse had a fractured neck, and if I’d just gone in and adjusted the horse there could have been severe consequences.”

Kaneps agrees that equine chiropractic adjustment is a well-tested modality, and those trained in it should perform treatment.

Vibration Plate Therapy

The next time you watch a sporting event, notice how the athletes “jump” around on the sidelines, readying themselves for play. Turner likens the benefits of vibration therapy in horses to those loosening routines.

The gentle motion is believed to increase blood flow, lessen joint pain and inflammation, and warm and loosen muscles, which reduces horses’ muscle tension before a ride. Research findings on the effects of whole-body vibration are mixed. One example is a Michigan State University study in which researchers subjectively found no difference in flexion, stride length, or heart rate after vibration therapy, but horses exhibited behavioral changes such as relaxation and less stress.

In another study, out of Peninsula Equine Medical Center, in California, a researcher found that hooves grew faster after two months of whole-body vibration. Further, this vet and colleagues plus one from Western University of Health Sciences College of Veterinary Medicine observed an increase in back muscle size and symmetry after twice-daily whole-body vibration treatments five days a week for 60 days (Halsberghe et al., 2017).

“In general, horses really like it,” says Gabrielle Solum, DVM, a resident at Equine Sports Medicine and Rehabilitation, in Whitesboro, Texas. “They yawn and relax on there, so it’s a nice therapy for them to have. The biggest thing is if you achieve benefits like increased hoof growth and larger back muscles, it must be used daily and (you need to) recognize that there is no prolonged effect if you stop using the modality.”

Pulsed Electromagnetic Field (PEMF) Therapy

This approach uses pulsating magnetic fields, made by pulsing a small electrical current through wire coils, to jump-start and accelerate normal biological cellular reactions. Most of the information on PEMF therapy is on bone healing. Proponents say PEMF increases circulation and decreases pain and inflammation to accelerate healing.

“It is really good for muscle relaxation … when an animal is relaxed, they hold themself differently, and we want a horse to bear its weight correctly,” Turner says.

Pulsed electromagnetic field therapy is just one type of electrical stimulation treatment. One of Turner’s go-to modalities that also falls into this category is functional electrostimulation (FES), which works to strengthen a muscle that is not being used and can provide pain relief. This mimics nerve patterns signaling the muscles to contract, and he has found it particularly beneficial when an area has been inactive following an injury.

“Functional electrostimulation has a lot of uses,” Turner says. “It can be particularly helpful for horses needing multiple spinal or skeletal adjustments. The electrostimulation helps fatigue the muscles so you can better work on an area.”

Ice/Cryotherapy

Since the dawn of human sports medicine, doctors and surgeons have recommended ice baths to decrease inflammation and reduce pain. Solum says this easy-to-use treatment is underutilized.

“Ice boots are great to use after exercise for 20-30 minutes to decrease inflammation,” she says. “There are a lot of ice boots on the market, but it’s also acceptable to use a bucket of ice if your horse will tolerate it.”

She often pairs ice with heat, especially for horses with back pain or those performing athletically.

“You can place a warm towel on the horse’s back or use one of the microwavable products for humans,” says Solum. “I probably wouldn’t use an electric heating pad, but there are benefits to using heat along the axial skeleton to give more mobility and prepare the horse to be athletic. Then I’d follow that up with ice after activity.”

Be cautious about the material’s temperature; you can damage tissue if it’s too hot. If you cannot tolerate the heat on your skin, it’s unlikely the horse can.

Be sure to discuss ice and heat therapy with your veterinarian before using them on your horse, because in some situations one is more beneficial (or could be detrimental).

Maintenance Begins with Fitness

Complementary therapies offer diverse options for enhancing performance and well-being. Boldt says collaboration with veterinarians and integration with conventional therapies are key factors in developing a holistic approach to maintaining performance horses.

“Integrative therapies are another tool in the toolbox—another therapy we can use with conventional therapies,” he says. “They can’t be used for everything, and I’m an advocate that they are done by a veterinarian.”

Although it can be argued that conditioning and exercise fall under rehabilitation, our sources here agree they are fundamental. Kaneps explains that people don’t run a 10K or a marathon without proper training. If they do, they are likely to sustain an injury. The same is true in equine athletes.

“Rehabilitation and conditioning exercise are the basis for having a good, strong equine athlete who is capable, and it hopefully helps prevent injury,” he adds. “When we see a horse with a sore back, we may use laser, shock wave, injection, or acupuncture, and the pain may be removed. But ultimately the horse needs to build core strength, topline strength, and flexibility and through exercise to build up that core.”

Q: With summer approaching, I want to be sure I’m prepared to minimize unpleasant odors on my farm that are always worse during the warmer months. What can I do to eliminate those odors or prevent them altogether?

A: During the warm season horse properties can develop odors—between muddy turnouts, stockpiled manure, and urine buildup in confinement areas. These spots attract pests such as flies and rodents and can raise concerns among neighbors. Inhaling ammonia in stalls, barns, or confined spaces can also harm a horse’s respiratory tract. Here are five tips to help you reduce odors on your horse property.

1. Start With Healthy Soil

Odor control starts with a step many people overlook: Start with healthy soils and slightly sloped ground. If you confine horses in a low, wet area you will end up with mud and odor problems. Make sure you have a good, even slope (about 1-2%) away from stalls or shelters. Be sure to grade the ground, making it even before putting gravel or another type of footing in these areas. Otherwise, any depressions in the underlying soil allow water (and urine) to pool under the gravel, potentially causing odors.

2. Develop a Manure Management Program

A solid manure management program goes a long way in solving odor issues. Begin by picking up manure every one to three days in confinement and high-traffic areas. Establish your manure pile far away from streams, ditches, rivers, or other bodies of water to prevent runoff contamination, and cover it with a tarp (to keep it from getting soaked by rain).

Let’s say you’ve picked up manure and you still have odors. The simplest and cheapest solution might be to drag or harrow the paddock. This helps get beneficial aerobic microbes back in your soil that break down tiny, odor-causing organics. It also helps the ground dry faster.

3. Minimize Moisture

Keep your farm as dry as possible by removing opportunities for standing water to form. Keeping shelters, stalls, and barns dry, or at least well-drained, goes a long way in reducing odors. Moisture often triggers odor problems; wet areas release more odor-causing compounds than dry ones. Consider doors, screens, or roof overhangs for shielding barn openings from rain. Invest in good working gutters and downspouts, which divert rainwater away from buildings and confinement areas. Ventilation also helps dry the barn area by releasing and not trapping moisture and allowing odors to dissipate. Stall windows, open doorways, cupolas and vents in roofs, ceiling fans, etc., can all improve ventilation in your barn.

If a horse perpetually urinates in one spot in a confinement area, you might have to occasionally dig out and refresh footing in that spot to help it dry thoroughly.

4. Use Microbial Sprays to Minimize Odors

A variety of microbial spray products are available, which you can use on urine spots and across confinement areas to neutralize odors. These products contain different types of beneficial bacteria, enzymes, and/or fungi. They come in highly concentrated solutions that you dilute and spray on paddock areas with a garden sprayer. The beneficial microbes break down ammonia and organic material that cause odors and attract flies. Use these animal-safe solutions as often as needed to control odors. You can commonly find these beneficial microbial sprays at organic garden supply companies or feed stores.

5. Use Zeolite Products in Stalls

Zeolite products remove odors effectively when you sprinkle them in stalls or other areas of your barn. These naturally occurring minerals have a highly porous structure, which binds with ammonia molecules in urine, eliminating odors. You’ll find zeolite, which looks like finely ground kitty litter, in several stall deodorizer products.

Take-Home Message

Starting with healthy soil, developing a manure management program, minimizing moisture, and using microbial sprays and zeolite products can all help reduce the odors on your horse farm. In turn, this will minimize pests and support your horses’ comfort and well-being.

If you’ve ever managed a horse with back pain, then you’ve probably heard the term kissing spines floated around. But what exactly are kissing spines, and what does it mean if your horse is diagnosed with them?

Kissing spines, or overriding spinous processes, are reported to be one of the most common causes of back pain in horses. Though back pain was originally described in the 1960s, it wasn’t until recent years that veterinarians and researchers devoted more attention to it as a primary problem in horses as opposed to secondary to hind-limb lameness. As technology has progressed to produce higher-quality X rays and our knowledge of equine back anatomy’s complexity has expanded, we have a greater appreciation for and understanding of kissing spines.

A horse’s spine is composed of individual vertebrae connected by ligaments and surrounded by muscles. Each vertebra has a bony prominence that sticks up—the spinous process. In a normal horse, the spinous processes are spaced evenly, allowing a horse to both flex and extend his back. With kissing spines, the spinous processes are too close to each other or even touching. The lack of space between processes reduces back mobility and causes pain during movement as the spinous processes interfere with each other.

The underlying cause of kissing spines is still largely unknown. The condition can occur in any horse, but some breeds, such as Thoroughbreds and Warmbloods, seem to develop it more than others. Horses are most commonly diagnosed around 5 to 10 years of age, but younger and older horses can develop it, too. Kissing spines typically occur in the last few thoracic vertebrae—right where a saddle and rider would sit along the horse’s back.

Horses with kissing spines can demonstrate a variety of clinical signs. These can be subtle, such as poor performance or decreased range of motion when asked to flex or extend the back, all the way up to more noticeable behaviors, such as a painful reaction to back palpation, reluctance to be saddled or ridden, cross-­cantering, and bucking under saddle.

Veterinarians typically diagnose kissing spines using a combination of clinical signs and X rays of the horse’s back. X rays are the best way to assess the distance between spinous processes and to look for evidence of problems in the bones, such as increased density or ­cysticlike lesions. The tricky aspect of diagnosing kissing spines is that researchers have shown that 39% of horses have changes on their back X rays consistent with kissing spines, yet they show no signs of back pain. Similarly, the angle from which the veterinarian takes the X rays can influence the apparent spacing between processes and might result in overdiagnosis.

​Other diagnostic modalities your veterinarian might use include nuclear scintigraphy (bone scan), ­ultrasonography, and the injection of local anesthetic around the suspected painful spinous processes. Unfortunately, each of these modalities has its limitations. For example, injecting local anesthetic into the area does not produce reliable diagnostic results, meaning veterinarians cannot predict which horses will respond to treatment. Therefore, the most reliable way to diagnose kissing spines continues to be looking at changes on back X rays in conjunction with clinical signs of back pain.

Once a veterinarian diagnoses a horse with kissing spines, he or she can proceed with several treatment options. In mild cases horses might respond to conservative treatments such as muscle relaxants, chiropractic and acupuncture therapy, shock wave, or local corticosteroid injections. If a horse does not improve with conservative therapy or it’s a more advanced case, the veterinarian might recommend surgery. The surgical treatment might involve either cutting the ligament that runs between each spinous process at the affected sites to allow more space between them or removing part of the spinous process to create more space. The procedure the surgeon elects to perform mostly depends on the severity of the kissing spines. Surgery has been shown to produce more favorable long-term results than medical therapies in horses with this condition.

Back pain in horses can be complex. While kissing spines is the most common cause in horses, the diagnosis should not be made on X rays alone. Rather, the veterinarian should assess X rays in combination with clinical signs of back pain and only after ruling out other causes of lameness. Once your veterinarian makes a diagnosis, there are many treatment options that can help get your horse back on track and moving pain-free.