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.

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.”

Why is it so difficult for equine veterinarians to change prescribing practices? That’s the question Clare Ryan, DVM, PhD, Dipl. ACVIM-LA, from the Department of Infectious Diseases, at the University of Georgia’s College of Veterinary Medicine, in Athens, posed during her presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11 in Orlando, Florida. One reason, she said, is that changing behavior is challenging.

“Things always come up that keep us from making changes that we know are important … we are busy!” she said. “And with push back from clients when we try to change our behavior, it can be even more difficult, especially when trying to step away from the higher-tier antibiotics toward first-tier antibiotics.”

Ryan used ceftiofur as an example: “It’s a fantastic drug,” she said. “A third-­generation cephalosporin with activity against both Gram-positive and -­negative microbes approved for Streptococcus equi respiratory infections and, of course, effective for many off-label conditions. It is widely available, affordable, convenient to administer, especially if needed long-term, and usually has few adverse effects.”

A big downside, Ryan said, is the significant impact cephalosporin resistance has on treating serious infections in humans. The potential impact is so big, the World Health Organization classifies ceftiofur as an HPCIA (highest-priority critically important antimicrobial), meaning it should be used sparingly in equine practice.

“The University of Georgia has an antimicrobial stewardship committee to help guide prescribing practices for hospital veterinarians, and they have a tier system,” Ryan explained. “In this system, ceftiofur is tier 2, not first-line therapy.”

When is it appropriate to use ceftiofur? Ryan described a litmus test to find out:

1. Is ceftiofur effective at treating the bacteria causing the infection? Enterococci, Pseudomonas, and Salmonella are inherently resistant to cephalosporins.
2. Is the cultured organism’s minimum inhibitory concentration (MIC) above the reported MIC break point?
3. Can ceftiofur reach adequate concentrations at the infection site? It cannot in the meninges, placenta, or joints.
4. Are reasonable alternatives available, such as beta lactams (penicillin, ampicillin), sulfas, tetracyclines, or gentamycin, that are not HPCIAs?

For which clinical conditions is ceftiofur use appropriate? Ryan explained the Gram-positive respiratory infections it is labeled for (at times combined with an aminoglycoside for Gram-negative coverage), urinary tract infections, and potentially some cases of endometritis with Gram-­positive organisms.

“If treating foal bronchopneumonia, fresh wounds/lacerations, following choke, for surgical prophylaxis, or strangles, we really should be looking for the lower-tiered drugs,” she said.

Further, she emphasized that we should reach for nonantibiotic therapies and employ vaccination, improved husbandry, and biosecurity protocols to prevent disease.

How can you start making changes in your antibiotic-prescribing habits?

“Be curious about antimicrobial stewardship,” said Ryan. “Start by picking small things and implement one at a time. Don’t think you’re going to suddenly be a perfect antimicrobial steward in one afternoon.”

Also, find a like-minded colleague and develop your own antimicrobial use guidelines, holding each other accountable and leading the way for other practitioners to follow suit.

Mats Troedsson, DVM, PhD, Dipl. ACT, DECAR, of the University of Kentucky’s Maxwell H. Gluck Equine Research Center, in Lexington, Kentucky, addressed antimicrobial resistance (AMR) from a reproduction standpoint during a presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida. 

In theriogenology, veterinarians use antibiotics to not only treat infections but also improve reproductive efficiency in the absence of illness. They often administer antibiotics in post­breeding intrauterine infusions, following natural mating, during embryo transfer, and in semen extenders for artificial insemination without evidence of infection. 

Breeding-induced or physiologic endometritis (inflammation of the endometrium, or uterine lining) is predominately triggered by the presence of sperm, not bacteria, in the uterus. The purpose of this inflammatory reaction is to eliminate excess sperm and any contaminating bacteria and inflammatory products to allow a hospitable environment for the embryo.  

Recent data show, however, that almost 30% of mares clear the uterus of inflammation within six hours of breeding/insemination/embryo transfer, and approximately 85% of broodmares are resistant to persistent endometritis. 

“This emphasizes how effective the uterine defense mechanism is,” said Troedsson. 

For mares that can’t clear the inflammation, we need to ask why, he said. 

“We have previously shown that these mares have impaired myometrial contractility in response to inflammation due to accumulation of nitric oxide in the uterus as well as an imbalance between pro- and anti-inflammatory cytokines in response to breeding,” said Troedsson. “Predisposing factors can also include poor perineal conformation.” 

When a mare fails to clear bacteria from the uterus, antibiotics are indicated and should be selected based on culture and sensitivity results. Treatment should continue for three to five days and can be combined with uterine lavage if fluid is present. Note that mares diagnosed with bacterial endometritis will not be bred in the same cycle, so there is time to wait for the laboratory results to guide treatment, he said. 

In the case of treatment failures, consider the presence of resistant or dormant bacteria located in the deeper layers of the endometrium or endometrial glands or the presence of biofilm. 

“bActivate is a sterile growth medium that activates dormant Streptococcus zooepidemicus after being instilled in the uterus,” said Troedsson. “The uterus can be cultured the day after activation and the mare treated if the culture is positive. If the culture is negative, the uterus is clear.” This also works for other bacteria, he noted. 

In the case of persistent infectious endometritis that doesn’t respond to treatment, biofilms that evade both the immune system and antibiotics could be to blame.  

“Bacteria on the surface of the biofilm are exposed to sufficient concentrations of antibiotics, but reduced diffusion through the biofilm matrix leads to decreased concentration of antimicrobials within the biofilm community,” he explained. “This provides an excellent opportunity for bacteria to develop AMR. Further, genetic alterations associated with AMR are easily transmitted between bacteria in the biofilm, contributing to AMR.” 

To treat these infections, vets must first diagnose or suspect a biofilm, then break it down. “Biofilms are very difficult to diagnose in the field,” Troedsson said. “One potential way of diagnosing biofilms is to identify proteins or lipids specific to biofilms. If those molecules can be consistently recovered from mares with biofilms, an in vivo assay can be developed.” 

While veterinarians must treat endometritis using antibiotic therapy, Troedsson ­recommends treating breeding-induced endometritis with ecbolics, lavage, and possibly immune modulators, such as bacterial cell wall fractions (Settle), platelet-rich plasma, dexamethasone, or lactoferrin. 

“Antibiotics are not the first choice,” he stressed. “We know it is semen, not bacteria, causing the inflammation and subsequent uterine fluid.” 

Troedsson concluded by stating that while antimicrobials are valuable in equine reproduction for proven infections, using antibiotics to assist reproductive efficiency in horses with no health and well-being issues poses a challenge to equine practitioners. 

“We need alternatives to antibiotics, and decisions should be made based on scientific data rather than traditions and habits, such as routinely using antibiotics to flush mares 24 hours post-mating,” he said. 

A key strategy for reducing antibiotic use in equine practice is to limit prophylactic administration and only treat horses with evidence of infection. 

“Every time we prescribe an antibiotic, we are creating a potential risk of resistance, both the pathogen causing the disease and the natural flora of the patient,” said Pamela Velarde, DVM, a resident in large animal medicine at Cornell University College of Veterinary Medicine’s Department of Clinical Sciences, in Ithaca, New York. “Minimizing the use of the World Health Organization’s list of high-priority and critically important antimicrobials (HPCIAs and CIAs) in our veterinary patients is imperative, and antibiotics in general should only be prescribed when infection is documented and clinically significant.” 

Velarde and colleague Gillian Perkins, DVM, Dipl. ACVIM, recently completed a retrospective study of antimicrobial prescribing practices at Cornell’s Veterinary Teaching Hospital to identify areas of possible improvement. They presented their findings at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida. 

In 2021 about one-third of equine patients seen at the hospital were prescribed systemic antimicrobials—including a small percentage of HPCIAs—to treat infections affecting the musculoskeletal, upper respiratory, reproductive, gastrointestinal, and other systems. 

“Out of the 543 horses prescribed an antibiotic, no evidence of infection existed in almost half of the horses,” said Velarde. “Only a small percentage (< 15%) of the horses prescribed an antibiotic had confirmed infections based on culture.” 

For horses undergoing surgery, all were treated with antibiotics, including many horses that had what were considered “clean” surgeries (i.e., elective procedures performed on clean, nontraumatic, and noninflamed surgical sites that didn’t involve opening up the abdomen). 

“Key findings of our data were that approximately a third of the horses were prescribed antibiotics, and culture and sensitivity were only infrequently done,” she said. “Overall, limited prescriptions included HPCIAs. These data suggest that we can do a better job of antimicrobial stewardship for cases with no evidence of infection and for clean surgeries. We need to continue to critically evaluate if horses in these scenarios should be prescribed antimicrobials at all.” 

The next phase of this study is to establish antimicrobial stewardship guidelines for the hospital using a three-tiered approach following WHO guidelines on medically important antimicrobials: increasing justification for use, need for culture and sensitivity, and approval by the Infection Control Committee. 

During a presentation devoted to responsible antimicrobial use and selection at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11 in Orlando, Florida, Lucas Pantaleon, DVM, MS, Dipl. ACVIM, MBA, a veterinarian advisor at DVM One Health, in Versailles, Kentucky, referred to antimicrobial resistance (AMR) as a “silent pandemic” that we must address with a One Health framework approach.

“Antimicrobial-resistant bacteria can develop, disseminate, and have impacts on human, animal, and environmental health, incurring a huge economic burden,” he said.  

Pantaleon said we will never be able to completely defeat AMR because bacteria have an innate capacity to acquire resistance to drugs that were once effective. Instead, he urged veterinarians to be judicious with their use of antimicrobials to delay the onset of AMR and preserve the drugs we have today.

Pantaleon shared data from a systematic review published in the journal Lancet in 2022 stating that in 2019 there were 1.3 million human deaths attributed to AMR infection and almost 5 million deaths associated with AMR globally. Researchers on a study by the Centers for Disease Control (CDC) relayed that about 3 million people per year are affected by AMR infections, and an estimated 35,000 deaths annually are due to multidrug-resistant bacterial infections. If ignored, by 2050 AMR could cause 10 million deaths globally, with a $100 trillion price tag.

“Today, in the U.S., equine practitioners have the freedom and great responsibility to use any antibiotic to treat patients, because there is no regulatory body guiding antibiotic use in this sector,” he said. “AMR is a wicked problem where the solution requires a large number of people to change their behaviors.”

Pantaleon recommended including behavioral sciences and communication experts to transmit messages regarding AMR to the public.

Even using a One Health approach working across all disciplines in animal, human, and environmental health, Pantaleon warned equine practitioners, “We have monumental challenges ahead of us.”

In equine practice, he said, we must better address how to keep animals healthy, so we don’t need to use antibiotics in the first place. We need better, faster, and ­economical stallside diagnostic testing; improved biosecurity and infection prevention; and regulatory framework to guide us on how to be better with our drugs.

“Antibiotic use must not be a ‘cover-up’ for poor management or suboptimal infection prevention practices,” Pantaleon stressed.

For example, should veterinarians be using an aminoglycoside with every joint injection given the low risk of intra­articular infection? Do we need to infuse every mare post-breeding with antibiotics? Pantaleon said equine vets have many opportunities to improve antibiotic use.

In closing, Pantaleon acknowledge that equine veterinarians have many opportunities to improve our use of antibiotics to combat antimicrobial resistance.

Hoof wall defects are common in sport horses presenting with lameness and loss of use. Successfully managing these horses requires an understanding of why the hoof wall cracks, said Stephen O’Grady, DVM, MRCVS, of Virginia Therapeutic Farriery, in Keswick, during his presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Why Do Quarter Cracks Occur in Horses’ Hooves?

Quarter cracks in the hoof arise from overloading one side of the horse’s foot, generally the inside—toward the midline. “You won’t see a quarter crack without hoof capsule distortion,” said O’Grady. “And that distortion is going to be caused by an asymmetrical landing, where the lateral (outside) side of the horse’s foot contacts the ground first, then overloading the medial (inside) aspect of the foot. Over time, when the hoof wall can no longer take the excessive loading, it cracks.”

Hoof capsule distortion means the capsule changes shape from what is considered normal or healthy. That distortion relates to the horse’s conformation and how the foot lands on the ground.

Most horses with hoof capsule distortion have a rotational deformity, which means the bone alignment is straight, but they have a narrow chest, and their limbs rotate laterally.

Corrective Shoeing for Quarter Cracks in Horses

“Again, if you have a quarter crack, you have a distorted foot,” said O’Grady. To manage this, take the shoes off for 10 to 14 days and trim the heels so the heels and frog are on the same plane.

“Once everything is on the same plane, there is load sharing by all the structures, and the heels drop down and relax,” O’Grady said. He typically puts a spider plate on these horses. This shoe type protects the heel and redistributes the load to the lateral aspect of the foot.

O’Grady also recommended moving the shoe laterally with an extension. “The shoe can be placed tight or flush on the medial side but then has a one-quarter- to three-eighths-inch extension on the lateral side,” he said. “This moves the center of pressure to the better side of the foot.”

Take-Home Message

Hoof wall defects, such as quarter cracks, can lead to lameness in horses, especially if left untreated. Quarter cracks occur when a horse unevenly loads one side of the hoof as he travels. Farriers can manage quarter cracks using corrective trimming and shoeing, which can help balance the pressures placed on the hoof.

Soft tissue injuries involving tendons and ligaments are common in sport horses and generally require six to 12 months to heal completely. A rehabilitation plan helps the horse heal and build strength over time and reduces the risk of reinjury, said Katie Ellis, DVM, MS, Dipl. ACVSMR, a clinical assistant professor and section head of field services at the University of Georgia’s College of Veterinary Medicine, in Athens. Ellis outlined how she rehabilitates sport horse soft tissue injuries at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.  

The Ideal Rehabilitation Plan for Equine Soft Tissue Injuries

Ellis outlined her preferred rehabilitation plan for sport horses with soft tissue injuries as follows:

Months 1 and 2

• Stall rest with hand-walking.
• Physiotherapy (i.e., carrot stretches).
• Icing the affected limb once or twice daily.
• Administering topical and/or systemic anti-inflammatory drugs.
• Applying standing wraps to the affected limb and its opposing limb when the horse is stall-kept.
• High-power laser therapy applied by a veterinarian or supervised technician.

Months 3 and 4

• Stall rest with walking under saddle (”tack walking”).
• Walking over ground poles in hand.
• Continue all therapies and medications from the first two months.

Months 5 and 6

• Stall rest with walking under saddle and small amounts of trotting (depending on the type and severity of the injury)
• Walking over ground poles in hand.
• Icing the affected limb after riding.
• Continued physiotherapy.
• Standing wraps in the stall.

Months 7 and 8

• Stall rest with walking under saddle and trotting gradually included and interspersed throughout the ride (no trotting through turns).
• Walking over cavalletti (raised poles) under saddle.
• Physiotherapy.
• Icing the limb after work.
• Standing wraps in the stall.

Months 9 and 10

• Small paddock turnout added gradually (sedation provided by the veterinarian might be necessary).
• Canter work gradually included in under-saddle rehabilitation.
• Trotting and cantering through turns under saddle.
• Gradually adding cavalletti into under-saddle work.
• Physiotherapy.

Months 11 and 12

• Small-paddock turnout.
• Adding 20-meter circles and lateral movements (i.e., leg yielding) to ridden work.
• Physiotherapy.

Month 12 and Onward

• Normal turnout.
• Advanced/discipline specific maneuvers.

Rehabilitation for the Uncooperative Equine Patient

“Most patients will not follow the ideal example,” said Ellis. While some might not physically hold up to this plan, others might not be mentally capable of following it.

For horses not compliant with stall rest, Ellis typically recommends chemical intervention with a long-term sedation option such as trazadone or reserpine. Some horses do well in a stall with a small attached runout where they can walk outside without picking up any speed. Others might need to be turned out in a very small paddock next to other horses to remain calm during the rehabilitation process.

If a horse becomes dangerous to hand walk, Ellis sometimes recommends administering sedation before walking or, if the horse is cleared for it, starting to walk under saddle sooner than expected.

“If the horse is not compliant, I recommend adding more interesting exercises to keep them focused,” she said. “This might include ground poles, patterns, or even a walk around the property if the footing is safe.” In some situations she advises the owner pony the horse off a quiet horse in the early stages of rehab.

If the horse is too difficult to ride, Ellis might recommend increasing his turnout time sooner than planned and/or delaying ridden work. If safe for the individual horse and rider, she might choose to include light sedation for the early stages of ridden work.

Managing Client Expectations

“I find it can help the client to give them a time frame for total healing,” said Ellis. “My rule of thumb is six to 12 months for tendons and eight to 12 months for ligaments.” Having a timeline helps the owner stay on track with the rehabilitation plan and remain compliant throughout the process.

“Assure them the goal is to have the horse back in full work at the end of 12 months,” she said. For the clients that like to be very involved in their horse’s daily care, Ellis teaches them physiotherapy exercises to perform with them. She also has them use an electromagnetic blanket if they have access to it or balance pads as the horse progresses in his rehabilitation. “I find that giving them lots of other activities to do with the horse can help keep them busy and invested in the rehab.”

Repeat Imaging for Equine Soft Tissue Injuries

Ellis said she repeats imaging before increasing the horse’s workload and at every recheck, which she plans for every 30-45 days. “The imaging results rarely guide my rehab recommendations if the horse is improving clinically,” she said. “This just allows me to establish a new baseline.”

To check the horse’s clinical improvement Ellis watches the horse jog on a straight line but does not longe them in a circle. However, if the horse worsens during the rehabilitation process, she might perform a more extensive lameness examination or imaging to find the cause.

While diagnostic imaging technology and treatments for equine back pain have improved in recent years, the clinical examination remains a vital part of accurately diagnosing and treating spinal problems in horses. “Ninety-four percent of ridden horses experience back pain,” said Sandro Colla, DVM, MS, postdoctoral fellow at Colorado State University’s College of Veterinary Medicine & Biomedical Sciences, in Fort Collins. Colla explained the role of the clinical examination and functional assessment in diagnosing back problems in horses during his presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Equine Back Anatomy and Biomechanics

The horse’s back includes fascia, muscles, tendons, ligaments, and bones, which work together to support the horse as he moves and works. The fascia is a layer of connective tissue that surrounds muscles, providing support and structure. It contains nerve endings that can sense and send pain signals. Muscles and tendons work together to coordinate skeletal movement and provide stabilization at rest and during work, while bones protect the spinal cord and provide greater structural integrity, said Colla. Each piece of the horse’s back anatomy allows him to flex and extend both laterally (side-to-side) and longitudinally (dorsal-to-ventral) during forward and back global body movements—coordinated movements that utilize multiple muscle groups across the entire body to generate significant motion.

Dysfunction in the Equine Back

“Anything that impairs the physiological and biomechanical activities (of the spine) is considered dysfunction,” said Colla. Mechanical dysfunction renders tissues unable to execute their expected function and frequently has high clinical relevance, he added. Dysfunction caused by pain can be acute (conditions that develop suddenly and are often severe but short-lived), subacute (less sudden/severe), or chronic and observed in the horse’s posture, during palpation, and in spinal mobilizations.

“Horses can demonstrate normal, reduced, or increased spinal range of motion during examinations,” said Colla. This might be isolated to one joint or a whole segment due to bony changes, adhesions, abnormal muscle tone, or fascia pain, he added. “The clinical relevance of range of motion changes can vary but is usually associated with other dysfunctions.”

Veterinarians might also observe misalignments in the horse’s spine during examination, which can be isolated or evident throughout an entire segment of the spine. Misalignment can be congenital (present at birth) or acquired (developed after birth due to external factors) and generally has a variable clinical significance, said Colla.

Assessing Equine Back Pain

During a clinical examination, veterinarians should inspect the standing horse’s structure, noting any abnormalities or pathologies (disease or damage) found using palpation or imaging. However, the functional assessment allows practitioners to determine the clinical relevance of these findings and determine whether they affect the horse in his work, said Colla. “The functional assessment should be dynamic and include performance-related work.”

During an assessment Colla said veterinarians should ask clients to describe how long a horse has shown signs of back pain, characteristics of the horse’s pain, previous treatments and their successes, current athletic performance, and intended future use. They should inspect the horse both at rest and in motion and observe muscle development and any asymmetries. Then, using light palpation, they should locate any vertebral misalignment, increased temperature on any part of the back, or abnormal pain sensations.

“Gradually increase force applied to any structures of interest,” said Colla. “Find trigger points and put pressure on exactly that point to observe the horse’s reaction.”

Veterinarians can also observe how the horse moves during spinal mobilization exercises including sternal lifts, lateral bending/rotation, and lumbosacral flexions, said Colla.

Using objective measurement tools can help veterinarians accurately quantify abnormalities in a horse’s back. Colla said he often uses a flexible ruler to draw the contour of a horse’s spine to determine if his posture changes at any point during the rehabilitation, a pressure algometer to quantify pain, and a noncontact infrared thermometer to measure any areas of increased heat. He also takes pictures of the horse to refer to later if needed.

Diagnosing and Treating Equine Back Pain

“For horses with mechanical dysfunction, (veterinarians) can take radiographs, ultrasound, computed tomography, or bone scan (or a combination of several) to help determine the site of dysfunction,” said Colla.

In horses with dysfunction caused by pain, he uses these imaging modalities to locate any pathologies in the back. He also recommends manual therapies, systemic or local medications, acupuncture, extracorporeal shock wave therapy, and therapeutic exercises for rehabilitation.

Colla treats horses with range-of-motion restrictions using therapeutic exercises, manual therapies, and in cases of misalignment, chiropractic adjustment. The only way to treat misalignments is with chiropractic adjustments, he added.

Take-Home Message

Diagnostic technologies and treatments for equine back pain have improved in recent years, but clinical examination and functional assessment are still important for locating clinically relevant pathologies in a horse’s back. Veterinarians should approach each patient as an individual and develop a treatment plan based on the horse’s unique pain and the owner’s plans for the animal.

Veterinarians can use positron emission tomography (PET), computed tomography (CT), or magnetic resonance imaging (MRI) to help diagnose problems in equine patients, but how do they choose which to use? Timothy Manzi, VMD, Dipl. ACVR-EDI, clinical assistant professor of large animal diagnostic imaging at the University of Pennsylvania’s New Bolton Center, in Kennett Square, and Myra Barrett, MS, DVM, Dipl. ACVR-EDI, associate professor of equine diagnostic imaging at Colorado State University’s College of Veterinary Medicine, in Fort Collins addressed this nuanced question at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Positron Emission Tomography in Horses

More veterinarians are using positron emission tomography for its unique capabilities. Paired with motion-correcting software, PET can tolerate minor movement, making the modality ideal for use under standing sedation, rather than anesthesia, they explained.

Used both for screening and follow-up evaluations, PET scans allow the veterinarian to assess all four feet in 20 minutes and structures as high as the proximal suspensory ligament and distal (lower) knee and hock in most horses. The veterinarians agreed the modality excels at detecting subtle issues such as impending sesamoid fractures, which veterinarians might miss on standard radiographs. Positron emission tomography is popular in both racehorse and sport horse practice because it allows practitioners to identify subchondral bone injuries early.

Computed Tomography in Horses

Significant advancements in CT technology have enhanced its use in equine medicine. Specifically, fan-beam CT produces high-resolution images and can be performed under standing sedation. The alternative, cone-beam CT systems, acquire volumetric data (used to display a 2D projection of a 3D sample) but the veterinarians agree these systems are more prone to artifacts (unintended distortions) and less effective for soft tissue evaluation compared to the fan-beam CT.

Small-animal practitioners use cone-beam CT for dental imaging. Manzi said it has more limited use in equine medicine but still offers some good utility.

Veterinarians can also use CT to diagnose vertebral pathologies (disease or damage). Used in combination with myelogram contrast, CT can reveal spinal cord compression undetectable by radiographs. For imaging of the equine pelvis, the modality offers better detail than some other imaging modalities, uncovering conditions such as sacroiliac lysis that were previously only diagnosed post-mortem.

Magnetic Resonance Imaging in Horses

Magnetic resonance imaging remains a cornerstone for diagnosing soft tissue injuries and bone-marrow lesions, including bone bruises with fluid and contusions. While Manzi and Barrett described low-field standing MRI as more accessible, they agreed it is prone to motion artifacts and offers less detail than high-field MRI conducted under general anesthesia.

Diagnostic Imaging in Equine Practice

Veterinarians often use a mixture of imaging techniques to assemble the puzzle pieces they need to reach a diagnosis. Combining MRI or CT with PET can create a comprehensive picture, compensating for the blind spots of each modality. For instance, contrast-enhanced CT outperforms standing MRI in cartilage evaluation, while ultrasound remains superior for some tendon and ligament injuries, the clinicians explained.

Cross-sectional imaging (MRI, CT, and PET, which show slices of the structure imaged) can be particularly valuable when radiographs fail to reveal the source of lameness—in the case of bone marrow lesions, for example, said Manzi. To avoid client disappointment and frustration with inconclusive scans, both veterinarians recommend preprocedural education about the capabilities and limitations of each technology.

The Role of Artificial Intelligence

Artificial intelligence advancements attempt to simplify image acquisition and provide motion control, but that’s where its usefulness currently ends. “Imaging interpretation fully remains in the hands of veterinarians,” Manzi said.

Take-Home Message

Advanced imaging modalities can provide precise answers for equine practitioners, contributing to more precise treatments and better prognoses. Evolving PET, CT, and MRI technologies improve veterinary diagnostic capabilities, offering precise insights into pathologies that were previously difficult to define, and refine the way veterinarians identify and manage lameness in horses.

The Kester News Hour at the annual American Association of Equine Practitioners Convention highlights key advancements in equine research. In 2024’s edition leading veterinarians shared their top picks from recent studies in their area of practice interest. This rapid-fire session offers valuable insights into the latest findings from equine scientists worldwide.

Kyla Ortved, DVM, PhD, Dipl. ACVS, ACVSMR, an associate professor of large animal surgery from the University of Pennsylvania’s New Bolton Center, in Kennett Square was once again invited to present what she considered the most interesting, influential, and clinically relevant studies pertaining to the equine musculoskeletal system.

Study 2.5% and 4% Polyacrylamide Hydrogel (PAAG) in Horses

In the first study she described (Lowe et al., 2024), researchers characterized how a 2.5% synthetic cross-linked injectable polyacrylamide hydrogel (2.5% iPAAG) integrated with synovial (joint) fluid when they injected it into joints. In total the researchers injected 13 fetlock or knee joints with either 2 or 4 milliliters of 2.5% iPAAG, said Ortved.

They performed follow-up examinations on the horses on Days 0, 4, 42, and 90 after injection and found white blood cells in the synovial membrane (the joints’ inner lining) consistent with a reaction to a foreign body. By Day 42 they found the iPAAG completely integrated into the joint’s synovial membrane lining. “No adverse effects at one or two times the recommended dose was appreciated,” she added.

Ortved presented a second study (McClure et al., 2024), in which researchers conducted serial 4% PAAG injections in horses on Days 0, 45, 90, and 135, then evaluated the clinical, microscopic, and synovial fluid biomarkers in those joints. “No significant difference in joint effusion (swelling) or synovial fluid markers were found between the control and PAAG groups,” she said. “Microscopy showed a layer of the PAAG on the surface of the synovial membrane lining the joint; however, a small amount also integrated into the synovial membrane.”

Together, she explained, these studies showed that the hydrogels neither induced significant inflammation in the joint nor resulted in any negative side effects in healthy equine joints. “The 4% product functions as a viscoelastic supplement, remaining mainly in the joint space, whereas the 2.5% gel integrates into the synovial lining,” said Ortved.

Treating Equine Joint Pathologies with APS

Katie Seabaugh, DVM, Dipl. ACVS, ACVSMR, of the Translational Medical Institute at Colorado State University, in Fort Collins, shared findings from a study coauthored by Ortved, in which

researchers investigated the effects of a single intra-articular (IA) injection of autologous protein solution (APS) in horses with synovitis—inflammation of the synovial membrane.

Ortved and her team studied 18 horses; they injected one tarsocrural (the uppermost hock) joint in 12 horses with APS one day after inducing synovitis. They left six horses untreated as controls.

“While APS did not decrease lameness or joint circumference or alter synovial fluid parameters, gross pathology and histopathology scores were lower for APS treated joints compared untreated (control) joints suggesting that APS may have a disease-modifying effect,” said Seabaugh.

Using NSAIDs With Orthobiologic Treatment in Horses

Seabaugh presented a second study co-authored by Ortved in 2024 in which the research team examined if commonly used nonsteroidal anti-inflammatory drugs (NSAIDs)—either a single intravenous (IV) dose or single oral dose—had any effect on growth factor and cytokine (cell-signaling protein) concentrations in APS and platelet-rich plasma (PRP). Clinicians might use NSAIDs in conjunction with the processing of APS and PRP to reduce pain and inflammation in the horse’s body, especially in cases of injury.

“There was no significant difference in cytokines and growth factors, but NSAIDs were found in the final product,” said Seabaugh. “This means we need to use biologic therapies carefully in athletes that will be drug tested.” More research is needed using long-term NSAID treatment.

Treating Synovial Infections in Horses

Ortved described another study in which de Souza et al. (2024) investigated long-term survival of horses after synovial lavage of contaminated and septic synovial structures. They authors included 240 horses presenting with contaminated or infected synovial structures, including fetlocks, digital flexor tendon sheets, and tarsocrural joints.

She said survival rates were excellent following lavage, with 228 of the 240 (95%) surviving to discharge and 89% alive one year later. Variables associated with not surviving included forelimb involvement, heavier body weight, an unknown cause of sepsis, longer surgery times, and tendon sheath or bursa involvement, said Ortved. However, the researchers did not note a correlation between soundness and survival rate.

Using PET in Sport Horses

Finally, Ortved discussed a study in which authors demonstrated PET imaging, commonly used in racehorses to detect early injury was beneficial for sport horses. The researchers imaged 36 fetlocks using positron emission tomography (PET) and computed tomography (CT) and scored the radionuclide—the tracer practitioners inject before capturing a PET scan—uptake blindly. Thirty-two PET scans revealed a single area of increased radionuclide uptake, most often in the subchondral bone, which is beneath the cartilage. The most common sites were the inner part of the long pastern (medial first phalanx) and the upper inside joint surface of the knee or hock (dorsomedial condyle of the third metacarpal/metatarsal bones). These findings correlated with the CT images and the researchers identified an association with increased radionuclide update on PET scans and pain in the horses.

“PET uptake is common in sport horses, but the pattern of uptake is quite different from racehorses, likely due to differences in biomechanical loading in the joint,” said Ortved. “PET may be very useful in the early identification of bone lesions.”

Take-Home Message

Leading veterinarians chose these six studies due to the impact they had on equine musculoskeletal research in 2024. In this rapid-fire session they shared 2.5% iPAAG, 4% PAAG, and APS might be beneficial in treating horses with joint disease, but case selection is crucial. They also shared research proving veterinarians should be cautious when administering NSAIDs while collecting blood for APS and PRP, but single-dose administration is not likely to affect the final biologic product. In 2024, researchers also showed that synovial lavage might be an effective treatment for synovial infections and PET is an effective diagnostic tool for sport horses.

Many newborn foals need specialized care to address medical challenges that commonly arise during the first weeks of life. During their presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida, two board-certified internal medicine specialists—Laura Javsicas, VMD, Dipl. ACVIM, of Rhinebeck Equine, in New York, and Lisa Edwards, DVM, Dipl. ACVIM, ACVECC, of the University of Florida’s College of Veterinary Medicine, in Gainesville—shared their protocols for treating equine neonatal health issues in the field.

Diarrhea in Newborn Foals

Loose manure in foals can cause important health problems, with severity often varying by age. Neonates under 24 hours old with hemorrhagic diarrhea need immediate attention because this bloody manure can indicate clostridial (a type of bacteria) infection in the abdomen and an increased risk of sepsis (bacteria in the bloodstream). Diarrhea in foals over 2 weeks of age typically concerns practitioners less but still warrants veterinary care.

When managing foals with diarrhea, Javsicas and Edwards generally treat them with a di-tri-octahedral (DTO) smectite for toxin adsorption and intravenous (IV) fluids with dextrose for hydration and nutrition, and they conduct bloodwork to assess electrolyte imbalances, glucose and lactate levels, and renal function. Additionally, performing polymerase chain reaction (PCR) testing on the foal’s manure could help veterinarians identify the infectious agents.

Javsicas and Edwards said veterinarians prefer the antibiotic ceftiofur to treat diarrhea in foals and add metronidazole if they suspect a clostridial infection. The veterinarians added that ultrasound and nasogastric tube (NGT) placement are critical for identifying and relieving any gastric reflux in foals with diarrhea and coliclike signs.

Dehydration and Electrolyte Imbalances in Newborn Foals

Foal diarrhea poses a significant risk of dehydration and can lead to life-threatening electrolyte imbalances, especially hyponatremia (low sodium). For severe dehydration cases veterinarians can turn to a continuous rate infusion (CRI) of IV fluids. Balanced electrolyte solutions are ideal; veterinarians can also add dextrose and sodium bicarbonate (to counteract severe metabolic acidosis) if necessary, Javiscas said.

Both veterinarians recommended closely monitoring foals’ urine output during rehydration as a key indicator of kidney function. They also warned that despite practitioners’ best efforts to manage these cases on the farm, foals with severe electrolyte imbalances or signs of septicemia warrant a hospital referral.

Patent Urachus in Newborn Foals

A patent urachus occurs when the connection between the bladder and umbilical cord fails to close after birth. Veterinarians typically see this condition in foals that spend more time lying down than normal (i.e., “bed babies”), twins, or foals with abnormal or infected umbilical cords. They can treat most cases medically with antibiotics and local wound care, but regular ultrasound monitoring is important to assess the urachus and ensure there are no deeper infections, said Javiscas and Edwards.

Common patent urachus treatments include hypochlorous acid products and povidone-iodine (Betadine), which also have a skin-drying effect that can be beneficial in these cases, Javsicas said. Veterinarians generally only consider surgery if the condition doesn’t improve with medical treatment after 10 to 24 days.

Milk Replacement

Sick foals that cannot nurse need equine-specific milk replacers; Javsicas and Edwards noted that using milk formulated for other species can lead to diarrhea and electrolyte imbalances. If a neonate cannot nurse from its dam, veterinarians might use bottle or NGT feeding as alternatives. But if a foal can’t ingest milk from any source for any significant amount of time, veterinarians should provide IV dextrose supplementation and complete parenteral nutrition.

Take-Home Message

With strategic and resourceful field care, veterinarians can significantly improve outcomes for newborn foals affected by common health issues. Edwards and Javsicas emphasized the importance of thorough diagnostics, timely interventions, and informed treatments to protect neonatal health during this critical stage.

Aging mares play a key role in advancing equine breeding programs, but pituitary pars intermedia dysfunction (PPID), formerly known as equine Cushing’s disease, might interfere with their reproductive performance. Testing broodmares 15 years old and older for this disease and treating when needed might help minimize the negative consequences of PPID on mare fertility, said Sophia Panelli Marchio, DVM, a PhD candidate at Texas A&M University’s College of Veterinary Medicine, in College Station. Marchio spoke about the effects of PPID on mare fertility during her presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida

What is PPID in Horses?

Pituitary pars intermedia dysfunction is a neurodegenerative disease that progresses with age, with worsening clinical signs in older horses. Following stimuli such as stressful events, thyrotropin-releasing hormone, or TRH, stimulates melanotropes—cells that produce melanocyte-stimulating hormone—in the pars intermedia of the pituitary gland to express a gene called pro-opiomelanocortin (POMC). The body then breaks POMC into smaller hormones, including adrenocorticotropin hormone (ACTH). In turn, the horse’s body releases ACTH into circulation where it stimulates the adrenal gland to release a variety of compounds and hormones. 

Dopamine produced by dopaminergic neurons in the hypothalamus inhibits the production of ACTH and other POMC-derived hormones. Thus, horses with neurodegeneration of the dopaminergic neurons lose control over the production of ACTH and other hormones. Often, they overproduce these hormones and, as a result, hyperplastic growth—an abnormal increase in cell number—of the pars intermedia.

Recognizing and Diagnosing PPID in Horses

Classic signs of PPID include polydipsia and polyuria (excessive drinking and urinating), hyperhidrosis (extreme sweating), secondary infections, lethargy, neurologic problems, abnormal fat distribution, hirsutism (a long, shaggy coat due to abnormal shedding), hyperinsulinemia-associated laminitis (HAL), muscle wasting, and a pendulous abdomen.

Veterinarians most commonly diagnose PPID by measuring basal (resting) ACTH levels.

“If evaluating basal ACTH, veterinarians must appreciate that the reference values will change based on season,” said Marchio. “ACTH values can also differ if the animal has been through a stressful situation.”

Effects of PPID on Mare Fertility

In addition to the clinical signs mentioned above, broodmares with PPID might experience an absence of seasonal anestrus, abnormal cycles, anovulatory follicles, subfertility, recurrent endometritis, and abnormal lactation.

“Dopamine plays an important role in controlling reproductive hormones,” said Marchio. “It regulates reproductive seasonality and inhibits cyclicity during the anovulatory season.”

The POMC-derived hormones, including ACTH, increase in mares with PPID. To determine the effect of high ACTH on reproduction, researchers on one study (Hedberg et al., 2007) treated healthy mares with ACTH. “They found a higher concentration of steroid hormones that inhibit gonadotropin-releasing hormone (GnRH) release and an increase in cortisol,” said Marchio. “In turn, high cortisol can repress GnRH as well as luteinizing hormone (LH) release. Further, high follicular fluid cortisol levels can disrupt oocyte quality.” Researchers on another study of healthy mares treated with the synthetic glucocorticoid dexamethasone also reported a reduced LH concentration (Asa et al. 1982).

“Only one study clearly correlates ACTH with impaired reproductive performance (Tsuchiya et al., 2021),” said Marchio. “As ACTH increased, cortisol increased, and mares had lower reproductive success determined by live foaling rates.”

Marchio also said researchers believe the enlargement of the pars intermedia can compress the pars distalis and interfere with the production and release of follicle-stimulating hormone (FSH) and LH, impairing the mare’s cyclicity. They also hypothesize that recurrent endometritis might develop due to the immunosuppressing effects of high cortisol levels.

Treating Broodmares That Have PPID

Administering a dopamine agonist such as pergolide (an FDA-approved dopamine receptor agonist labeled for treating clinical signs of PPID) or cabergoline (another dopamine receptor agonist) and good management practices improve the well-being and reproductive performance of aged broodmares with PPID, said Marchio.

“Be certain to suspend pergolide treatment at least 30 days before foaling and implement the treatment 30 days after foaling as it can interfere with lactation,” she added.

Take-Home Message

Formerly known as equine Cushing’s disease, PPID in horses might have negative effects on mare fertility. “We only have hypotheses on how PPID affects reductive performance,” said Marchio. “The exact mechanisms are still unknown and must be studied in depth utilizing horses with PPID.”

Equine asthma can affect horses of any age, breed, or discipline, making it harder for them to breathe properly and limiting their performance. The FDA has approved treatments such as inhaled ciclesonide for treating severe equine asthma, but these drugs’ efficacy in moderate cases is less clear.

Macarena Sanz, DVM, PhD, Dipl. ACVIM-LA, now an associate professor of equine medicine at Iowa State University, in Ames, along with her collaborators examined the potential benefits of inhaled ciclesonide for moderate equine asthma. The study, conducted while Sanz was at Washington State University (WSU), in Pullman, involved researchers from WSU, other Washington clinicians, and the University of Calgary, in Canada. Sanz and the team shared their findings in the Proceedings for the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Studying Ciclesonide in Horses With Asthma

Sanz and the research team studied 21 young racehorses confirmed to have moderate asthma over 10 days. They split the horses into two groups—one treated via an inhaler system with ciclesonide (12 horses) and a placebo group that use the inhaler without ciclesonide (9 horses). They blinded the researchers, trainers, owners, and grooms to the treatments.

The researchers performed a tracheal endoscopy on Day 0 and Day 10 and scored the  mucous present, bronchoalveolar lavage (BALF) cytology (looking at the cells under a microscope), and polymerase chain reaction (PCR) testing of BALF cell cytokines (cell-signaling proteins). They also asked the owners, trainers, and grooms to assess and score the horses’ respiratory signs daily.

In the horses treated with ciclesonide, the researchers noted improvement in the percentage of inflammatory cells and cytokines in the BAL F on Day 10. The owners, trainers, and grooms also noted a daily improvement in these horses’ clinical signs. “The treatment improved clinical signs, cough in particular, and decreased the percentage of mast cells in their bronchoalveolar lavage fluid, consistent with less inflammation,” said Sanz.

Clinical Applications and Future Ciclesonide Research

“We showed that treatment with inhaled ciclesonide can benefit young racehorses with moderate asthma,” said Sanz. Based on the team’s findings and because the inhaler system used in the study has been discontinued, Sanz said she and her fellow researchers believe veterinarians and researchers should evaluate the efficacy of ciclesonide administered through other available nebulizer systems.

“We showed a positive effect in young racehorses, but our study did not evaluate the duration of this response after the treatment discontinued,” said Sanz. She suggested following these horses for a longer period of time in future studies to evaluate the long-term efficacy of the drug.

Equine herpesvirus-1 (EHV-1), a significant cause of respiratory and neurological disease in horses, can spread stealthily at equestrian events, often going unnoticed. Nicola Pusterla, DVM, PhD, Dipl. ACVIM, AVDC-Equine, professor of equine internal medicine and epidemiology at the University of California, Davis, School of Veterinary Medicine, recently led research on the role that subclinical shedders—those that do not show signs of infection—play in spreading the virus. He presented his findings at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida, and raised concerns about current practices for detecting and managing EHV-1.

Silent Shedding and EHV-1 Environmental Spread

Horses that appear clinically healthy might still shed EHV-1 and contribute to outbreaks, complicating efforts to prevent viral spread. Pusterla’s research team tested 162 apparently healthy horses at a California horse show in April 2022. While only three (1.85%) horses tested positive for EHV-1 using quantitative PCR (qPCR), testing environmental samples from stalls revealed more positive results.

Immediately after the event the researchers collected sponges (specifically used to collect samples) from stalls and identified, among others, five EHV-1-positive stalls in one barn. “This clustering pattern confirms that the respiratory virus can easily spread among horses sharing close quarters and suggests that transmission might occur more subtly than we previously understood,” Pusterla said.

Focusing on EHV-1 Environmental Detection

The research team conducted a second study to evaluate the accuracy of environmental sampling in detecting EHV-1. They collected samples daily for 11 days using nasal swabs, stall sponges, air samples, and stall strips in an eight-stall barn housing seven adult horses aged 5 to 16 years old. Four horses had been vaccinated with a modified-live intranasal EHV-1 vaccine to mimic subclinical shedding; the remaining three horses were unvaccinated.

All intranasally vaccinated horses shed EHV-1 in nasal secretions at levels and for a duration similar to what is expected in subclinical shedders, while none of the controls had detectable EHV-1 in nasal secretions (the EHV-1 vaccine strain is harmless and cannot be transmitted to other horses, hence it does not contribute to the spread of EHV-1). The team used sponges to detect EHV-1 in the stalls of all vaccinated and one control horse. With stationary strips they detected EHV-1 in the stalls of three of four vaccinated horses but none of the controls. Air samples showed low detection rates, likely due to low concentrations of aerosolized EHV-1.

“The highest detection rates came from stall sponges, particularly in feeding areas where droplet contamination from nasal secretions is likely,” Pusterla said. The researchers established that the virus did not necessarily transfer directly between horses but did accumulate in shared and high-traffic spaces such as stall walls and water buckets.

Implications for Biosecurity at Equine Events

Pusterla’s research highlights the importance of implementing biosecurity measures to control EHV-1 at horse shows. He reported that traditional diagnostic methods, such as nasal swabs, are invasive and might miss shedding. Environmental sampling, particularly with stall sponges, could offer a more effective and practical approach to identifying viral clusters and taking preventive measures. However, the study’s limitations include a small sample size and no assessment of viral viability in the environment.

Take-Home Message

Pusterla emphasized the need for vigilant monitoring and proactive strategies to mitigate EHV-1 risks. Farm owners and managers should prioritize good biosecurity practices with their hygiene and cleaning efforts, especially in areas prone to droplet contamination, such as feeding zones and high-traffic areas. Equally important, environmental testing could be a vital tool for early detection and prevention of outbreaks, helping limit the silent spread of EHV-1.

Degenerative joint disease is a common yet complex condition among equine athletes, and managing it effectively often requires veterinarians to integrate multiple techniques.

During the Dec. 8 Sunrise Session “Tackling Degenerative Joint Disease: Real-World Case Studies,” presented by American Regent Animal Health, at the 2024 American Association of Equine Practitioners (AAEP) Convention, Sherry Johnson, DVM, MS, PhD, Dipl. ACVSMR, senior partner at Equine Sports Medicine in Pilot Point, Texas/Scottsdale, Arizona, and Kelly Zeytoonian, DVM, MBA, CERP, owner of Starwood Equine Veterinary Services, in Redwood City, California, described their multimodal approach to supporting a wide variety of equine athletes.

The Recovering Athlete

Background

The first case Johnson described was a 5-year-old Quarter Horse mare that competes in Western all-around events at Select and Level 4 Open (national) levels.

When the mare first developed clinical signs, she presented with a 3/5 left-hind lameness which localized about 30% to distal intertarsal (DIT) analgesia and 70% to a combination of tarsometatarsal joint (TMT) and DIT intra-articular analgesia. Previous hock injections with corticosteroids yielded minimal improvements, and ultrasound of the left-hind proximal suspensory ligament was unremarkable.

Hock radiographs revealed significant degenerative changes including subchondral bone sclerosis and lysis through the DIT joint, bridging osteophyte formation, and lysis and sclerosis through the distal tarsal interligament fossa.

Because the horse did not improve with rest and injections and the hock radiographs showed significant signs of advanced degenerative joint disease, Johnson recommended an MRI to get a more comprehensive diagnostic evaluation. MRI evaluation revealed moderate subchondral bone demineralization of the central tarsal bone extending to the level of the proximal intertarsal joint, as well as severe lysis and partial ankylosis (fusion) of the DIT joint.

Most worrisome was that the subchondral bone demineralization of the central tarsal bone was located within an area often prone to fracture. “Had we just injected this mare, shock-waved her and rolled on, the mare could have developed a slab fracture,” said Johnson.

Management Plan

Due to the extent and severity of the demineralization of the central tarsal bone, surgically facilitated distal tarsal ankylosis was not a viable therapeutic option for this mare. Therefore, Johnson had to employ a multimodal rehabilitative approach.

The mare spent a significant amount of time at Johnson’s rehab clinic, where she engaged in blood flow restriction (BFR) training, underwater treadmill work, proprioception exercises, resistance band training, and balance exercises. In addition, said Johnson, “the use of Adequan i.m.® (polysulfated glycosaminoglycan) became pivotal as part of this mare’s multimodal rehabilitation.”

When explaining her decision to use Adequan i.m. for this case, Johnson cited a 1993 study in which Burba et al. detected Adequan i.m. in horses’ cartilage and subchondral bone 96 hours following intramuscular injection. (Please see Brief Summary, including Important Safety Information for Adequan i.m., below.)

Outcome

Johnson reported this mare has gone on to set the NSBA World Championship Show record in Open Senior Western Riding and won the Open Level Western Riding at the AQHA World Show. She continues to compete successfully at the national level.

“This was not a Cinderella story, and I’m not here to tell you this mare is perfect every single day,” Johnson said. “But I do feel like with the intervention, with the multimodal approach, we were able to turn this mare around.”

The Actively Competing Athlete

Background

The next case Johnson described was a 14-year-old Quarter Horse gelding competing in youth Western all-around events. This horse had chronic osteoarthritic changes in his left carpus, including osteophyte formation on the medial aspect of the radiocarpal joint, bone sclerosis, and chronic joint capsule enthesopathy associated with wear and tear. Clinically, this horse had competed successfully with a long athletic career and seemed to like his job. His osteoarthritic changes had been managed for some time with corticosteroid injections and interleukin-1 receptor antagonist protein (IRAP) therapy.

Management Plan

Johnson employed a multimodal (biologic) intra-articular support program for this horse alongside shock wave therapy. In addition to continuing with therapeutic corticosteroids and IRAP, she recommended the use of Adequan i.m.® (polysulfated glycosaminoglycan).

Johnson’s decision to use Adequan i.m. for this case was supported further by Frisbie et al. (2009), who showed improved synovial membrane vascularity and less subintimal fibrosis associated with PSGAG treatment.

“What I want to provide is that consistent systemic support of articular cartilage health alongside these staged intra-articular therapies,” Johnson said. The goal in doing so is to block degradative enzymes to better maintain the horse’s long-term joint health.

The Unknown Athlete

Background

The first case Zeytoonian described was a 17-year-old Friesian-cross mare being considered for purchase for Training Level dressage. These were first-time horse buyers looking for a safe mount for their junior amateur daughter.

This mare had a history of hock and pastern injections every six months for multiple years with her current owner. During the prepurchase exam (which was not conducted by Zeytoonian), she was positive to distal forelimb and upper hind-limb flexions and was graded 1/5 lame on her left front.

These findings raised several questions with the potential buyers: “What does this mean for the horse’s long-term soundness? What will this mean for my daughter?” “How much money will I have to spend on management for this horse?” “Should I buy this horse?”

Without urging the buyers in one direction or the other, she reminded them this is an older horse that has been there, done that and will be safe for their kid. She told them just because the horse has had injections every six months doesn’t necessarily mean she needs them in perpetuity, especially with the change in workload. Ultimately, the buyers moved forward with purchasing the horse.

Management Plan

Zeytoonian’s approach for this horse was to pause her corticosteroid injections, introduce her to the new treatment program, and start her on systemic joint support with Adequan i.m.® (polysulfated glycosaminoglycan) to manage her arthritic changes. “My approach is always investing in systemic support,” Zeytoonian said.

Outcome

Zeytoonian reported the horse has now been with the junior rider for two years and has not needed her previous joint injections. She attributes this success to a change in management, a change in expectations for riding level, and a systemic approach to joint support.

The Hard-to-Treat Athlete

Background

The second case Zeytoonian described was a 17-year-old Appendix Quarter Horse gelding used as an advanced lesson horse with a history of chronic shifting hindlimb and forelimb lameness. The horse had done well with hock injections every six months for the past seven years. However, he eventually developed bony callouses in the hocks, which made them more difficult to treat.

At first, Zeytoonian shifted from treating the hocks with corticosteroids to Pro-Stride® APS. The horse’s condition ultimately progressed to the point of requiring radiographs to guide the injections, which wasn’t financially feasible for the owner. To complicate the situation further, the horse became lame on his left front when they were no longer able to treat the hind end.

Management Plan

The goal for this horse was to find an attainable, affordable solution that would allow him to continue in the owner’s lesson program. Zeytoonian dispensed Adequan i.m.® (polysulfated glycosaminoglycan) to the owner, and she gives the horse a full series every four to six months for her degenerative joint disease (DJD). The horse also receives Osphos® (clodronate injection) therapy and Equioxx® (firocoxib).

Outcome

Zeytoonian reported that two years later, this horse is still part of the lesson program and happy in his job.

Why Adequan i.m.?

Johnson and Zeytoonian have both had success incorporating Adequan i.m. into their multimodal programs to help manage difficult cases of degenerative joint disease.

“We feel really comfortable and supportive of Adequan i.m. being part of our program because we know that we get those levels of HA (hyaluronic acid) production within the synovial fluid and the cartilage within two hours after IM injection,” said Zeytoonian. “It doubles within two days and then remains there for four days,” as shown in a 1993 study by Burba et al.

Johnson said the frequency with which she administers Adequan i.m. for DJD is case-dependent. Generally, she recommends giving the horse a full course of treatment twice per year with monthly maintenance injections between.

Zeytoonian’s goal in prescribing Adequan i.m. is to implement timely intervention before horses diagnosed with degenerative joint disease start to feel sore. “Just like they need their flu/rhino vaccine every six months, they get a reminder that their horse is due for Adequan i.m. every six months,” she said about this group of patients.

BRIEF SUMMARY: Prior to use please consult the product insert, a summary of which follows: CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian. INDICATIONS: Adequan® i.m. is recommended for the intramuscular treatment of non-infectious degenerative and/or traumatic joint dysfunc­tion and associated lameness of the carpal and hock joints in horses. CONTRAINDICA­TIONS: There are no known contraindica­tions to the use of intramuscular Polysulfated Glycosaminoglycan. WARNINGS: Do not use in horses intended for human consump­tion. Not for use in humans. Keep this and all medications out of the reach of children. PRECAUTIONS: The safe use of Adequan® i.m. in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. For customer care, or to obtain product information, visit www.adequan.com. To report an adverse event please contact American Regent Inc. at 1-888-354-4857 or email pv@americanregent.com.

Reference

1. Burba DJ, Collier MA, Default LE, Hanson-Painton O, Thompson HC, Holder CL. In vivo kinetic study on uptake and distribution of intramuscular tritium-labeled polysulfated glycosaminoglycan in equine body fluid compartments and articular cartilage in an osteochondrial defect model. J Equine Vet Sci. 1993;13(12):696-703.
   
2. Frisbie, D. D., Kawcak, C. E., McIlwraith, C. W., & Werpy, N. M. (2009). Evaluation of polysulfated glycosaminoglycan or sodium hyaluronan administered intra-articularly for treatment of horses with experimentally induced osteoarthritis. American Journal of Veterinary Research, 70(2), 203–209. https://doi.org/10.2460/ajvr.70.2.203

PP-AI-US-1212

During her career, Lisa Fortier, DVM, PhD, Dipl. ACVS, James Law professor of surgery at Cornell University’s College of Veterinary Medicine, in Ithaca, New York and editor of the American Veterinary Medical Association’s journals, has made, and continues to make, contributions to developing and revolutionizing orthobiologics in equine medicine. In this field, practitioners use treatments derived from biological substances, such as stem cells, to manage musculoskeletal conditions.

Fortier presented her research on the history and future of orthobiologics, providing key takeaways for veterinarians using these therapies, during her Frank J. Milne State-of-the-Art Lecture at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida. She described the history of the main orthobiologics used today in equine practice: autologous conditioned serum (ACS), which concentrates platelets and interleukin-1 receptor antagonist protein, or IRAP; platelet-rich plasma (PRP); autologous protein solution (APS); and bone-marrow-derived cultured mesenchymal stem cells.

Which Orthobiologics Are Best for Horses?

“The main questions I get asked about orthobiologics are: ‘Which one is best?’” said Fortier. “‘How many injections should I perform?’ And, ‘When can we get the horse back to work?’” But, despite dedicating her life’s work to studying orthobiologics and implementing these in her practice, she said she’s learned these biologics are complex and there are still no clear answers to these questions. “There are a lot of different cells in play, and they change from horse to horse,” Fortier said. “None of the biologics are miracle drugs, but I still recommend orthobiologics as first-, not last-line, therapies.”

Fortier emphasized the importance of using orthobiologics to treat acute joint injuries involving an abundance of the pro-inflammatory mediator interleukin (IL)-1 . For example, Fortier recommended administering ACS at the time of injury, then following up with either additional ACS treatments or a 2.5% polyacrylamide hydrogel.

Platelet-Rich Plasma for Soft Tissue Injuries and Equine Joint Health

Veterinarians primarily use PRP in tendon and ligament injuries in horses, although physicians typically use the approach for treating joints in human medicine. “There is no scientific reason for this, it’s just the way it evolved,” Fortier said.

Veterinarians have not developed a true definition for what constitutes PRP, but they typically believe PRP contains five times more platelets than blood. The growth factors contained in those platelets are considered the active ingredient.

One of the key advances in PRP was discovering the need for leukoreduced PRP. “Leukocytes, also known as white blood cells, and one particular population of leukocytes, called neutrophils, are lightly inflammatory,” said Fortier. “When treating a musculoskeletal injury, we don’t need further inflammation, so using a leukoreduced PRP is advisable.”

When using PRP in practice, Fortier said she delivers it using ultrasound guidance, being careful not to overfill the lesion. She collects bone marrow during the same visit in case she wants to use stem cells moving forward because the stem cell culture process takes about eight weeks to complete.

Fortier also recommends using shock wave or pulsed electromagnetic field (PEMF) therapy for soft-tissue injuries. If she sees no response (i.e., 50% improvement in lameness), she reevaluates her diagnosis rather than simply repeating the PRP injection. If she does note a response, she’ll repeat the PRP injection in two weeks. A third injection is rarely in her repertoire. Instead, she’ll use the cultured stem cells or a 2.5% polyacrylamide hydrogel.

Autologous protein solution (APS) is an alternative to ACS (IRAP) and PRP, providing a patient-side means of delivering IL-1Ra and growth factors. This orthobiologic is produced from a patient’s blood sample incubated with special beads that stimulate cytokines and chemokines in 20 minutes (rather than overnight). APS has a much lower concentration of IL-1Ra than ACS (and both have more IL-1Ra than PRP) and yields a smaller volume. 

Bone Marrow and MSCs for Equine Injury and Joint Health

Fortier said bone marrow concentrate products fulfill the requisite trilogy for tissue repair: stem cells, cytokines (proteins that help regulate inflammation), and a scaffold that provides structural support for tissue development.

One of the key messages Fortier shared was the importance of using autologous products—biologics collected from the patients themselves. “Allogeneic cells, from another horse, induce an immune response, and that response can be massive following a second injection, possibly resulting in the loss of the horse,” said Fortier.

What Horses are Good Candidates for Biologics Treatment?

Regardless of which orthobiologics a veterinarian chooses, Fortier stressed the importance of starting with a systemically healthy horse.

“Nothing is going to heal if you have bad biology,” she said. “We’re becoming much more aware of subtle endocrine abnormalities, and these horses, who have a higher risk of tendon injury, will not heal as you might expect.” For this reason, Fortier recommends routine endocrine testing of all horses as part of their wellness program.

Take-Home Message

Veterinarians should examine horses’ overall health before considering them as candidates for orthobiologic treatment. The approaches veterinarians choose vary depending on each patient’s injury, disease, and health status, but they should treat a horse in the acute injury phase to increase the likelihood of success.

Working donkeys in Kenya need upper airway evaluations, yet equipment and hygiene limitations can make this task challenging. Anya Floyd, DVM, BSc, of Energy Equine Veterinary Services, in Alberta, Canada, described how to use a borescope double wrapped with sanitary sheaths to easily perform this task in less-than-ideal field conditions. Upper airway borescope examinations might help improve the welfare and working conditions of these animals.

“Donkeys are extremely hard-working animals,” said Floyd during her presentation at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida. “Their primary duty is pulling very heavy carts, and these carts and the harness system are rudimentary, tied directly to the neck below the jaw using feed sacks, rope, old pants … anything owner can find. Not surprisingly, this harness system can negatively affect the respiratory system, impacting welfare.”  

Uing an Accessible Borescope for Upper Airway Endoscopy in Donkeys

Recognizing the importance of examining the respiratory tracts of these animals, Floyd and her supervisor Martha Mellish, DVM, Dipl. ACT, of the Department of Health Management at Atlantic Veterinary College, in Prince Edward Island, Canada, purchased a simple 1.5-meter flexible borescope capable of capturing videos and images. The major concerns were:

1. Keeping the scope clean as it passed through the upper airways
2. Cross contamination when there was no reliable access to clean water, only alcohol towelettes

Floyd and her team used two disposable artificial insemination (AI) sanitary sleeves to double-wrap the borescope. Specifically, they cut one sleeve below the perforation, creating an opening at both ends of the sleeve. They fixed this open end was fixed to the camera (at the tip of the borescope) using electrical tape. The second AI sanitary sleeve had a sealed end, which they placed over the camera end to protect it while it was passed through the upper respiratory passages.

“Once the borescope was advanced through the ventral meatus (the widest and shortest nasal passage), the camera was advanced through the outer AI sleeve, revealing a completely clean scope and lens, ready to go,” said Floyd.

None of the donkeys were halter broke, so the veterinarians needed to apply chemical restraint and a nose twitch for the procedure.

Testing the Diagnostic Capabilities of the Borescope

Floyd performed 80 scopes in the field using this technique. She considered the scopes diagnostic if she could view the arytenoid cartilage, vocal folds, epiglottis, and trachea to a depth of 40 centimeters to 60 cm from nares (nostrils).

Unlike horses, “donkeys have narrow nasal passages compared to their head sizes, have fleshy and bulbous arytenoids, and the epiglottis is pointed,” said Floyd.

Lubricating the borescope to facilitate its passage helped limit trauma and hemorrhage during the procedure. Elevating the head made passing the scope easier as well.  

One inherent limitation the veterinarians discovered was the borescope’s excessive flexibility. It sometimes got kinked in an “S” shape the team couldn’t correct, so they had to withdraw the scope and reset it.

Take-Home Message

Performing upper airway endoscopy exams in working donkeys is important for their overall health and welfare; however, traditional endoscopes are not always available in some regions. Therefore, borescopes, which can be more easily purchased, might be a useful alternative when endoscopes are unavailable. “The borescope does not fully replace a traditional endoscope but can provide diagnostic data for respiratory health in donkeys,” said Floyd.

Mean glandular severity scores were significantly lower in the treatment group on Days 28 (shown) and 35, as seen on gastroscopy exam. | Courtesy Dr. Frank Andrews

Equine gastric ulcer syndrome (EGUS) refers to any ulceration inside a horse’s stomach. It often causes severe physical pain, leading to clinical signs such as behavior changes, weight loss, and loss of appetite.

Veterinarians view omeprazole as the mainstay EGUS treatment, said Frank Andrews, DVM, MS, Dipl. ACVIM, LVMA equine committee professor of equine medicine and director of equine health and sports performance at Louisiana State University’s School of Veterinary Medicine, in Baton Rouge. He spoke on the subject at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida. But because omeprazole might not be suited for long-term use, he said he and his team studied a schizophyllan—a beta-glucan—and hyaluronan product (relyneGI) to see if it could be useful in caring for ulcery horses.

Schizophyllan and Hyaluronan

Hyaluronan is a high-molecular-weight glycosaminoglycan in joint, intestinal, and gastric tissues. “It functions to maintain gastric and intestinal homeostasis, innate immunity, and modulates inflammation,” said Andrews. “In rats—which have a similar stomach to a horse with a squamous and glandular region—hyaluronan has been proven to protect the gastric lining and improve gastric mucosa integrity.”

Beta-glucans are an integral part of cell walls; schizophyllan activates immune cell maturation, differentiation, and proliferation. They have prebiotic properties and have been proven safe for use in horses.

Andrews and his team studied the efficacy of the new schizophyllan and hyaluronan gastric support supplement in 12 stall-confined Thoroughbred and Thoroughbred-cross horses with naturally occurring gastric ulcers. They divided horses evenly into treatment and control groups, performed gastroscopic exams, and weighed each horse at the start of the study after two days of acclimatization.

Over the 35-day treatment period the team gave 1 ounce (the high-stress dose) of the supplement three times daily in each treatment group horse’s feed and a 1-ounce dose of placebo three times daily in each control horse’s feed. They were blinded to treatments to avoid bias in scoring and repeated gastroscopies and weight checks on Days 14, 28, and 35.

Supplement Effects on Gastric Ulcer Scores

Andrews and his team saw a significant weight increase in all horses, but the treatment did not affect body weight. The mean nonglandular EGUS and severity scores were significantly lower in the treatment group on Days 28 and 35.

“The nonglandular ulcers were healed, except for mild hyperkeratosis (callousing), on these dates as well,” Andrews said. “The mean glandular (ulcer) and severity scores were significantly lower after 14 days in the treatment group. The ulcers did heal, but some reoccurred in both groups of horses by Day 28, which is not uncommon in these types of ulcers.” The mean gastric fluid pH remained low and variable throughout the study in both groups. Many drugs when used long term block gastric acid, which can change the stomach’s physiology. In other words, this supplement contributed to gastric health without changing stomach acidity.

Take-Home Message

Based on the research, Andrews said he believes the schizophyllan and hyaluronan supplement might have uses for managing horses with EGUS long-term and/or in conjunction with appropriate pharmaceutical treatment. (Supplements shouldn’t be used to treat disease but improve stomach health after discontinuing pharmacologic agents, he added.) The researchers observed clear improvement in nonglandular and glandular ulcer scores in the treatment group and did not observe any adverse effects from the supplement. The horses also readily consumed it, he added.

Andrews noted study limitations were a small sample size with limited breeds, a short treatment period, and that horses were stalled without exercise—management approaches that can be risk factors for ulcers. He hopes to address these limitations in future studies by finding out if the schizophyllan and hyaluronan product acts synergistically (a combined positive effect) with omeprazole or other drugs to improve gastric health in horses as well as prevent gastric ulcer recurrence.

Approximately 40 million working donkeys worldwide play key roles in the daily household economics of developing countries. These animals are responsible for pulling heavy loads in carts, often with improperly fitting harnesses that apply pressure on the neck. This can cause tracheal collapse and respiratory disease.

Carts fashioned for the approximately 10,000 donkeys in Meru County, Kenya, have a single shaft with a crossbeam attached to the donkeys proximal (closer to the base) to middle neck. “This means the weight of the entire cart is placed on the donkey’s ventral (underside of the) neck, directly overlying the trachea,” said Martha Mellish, DVM, Dipl. ACT, of the Department of Health Management at Atlantic Veterinary College, in Prince Edward Island, Canada.

Recognizing the impact of improperly fitting harnesses on the health and welfare of working donkeys, Mellish and colleagues investigated the presence of upper airway injury and tracheal collapse in both cart and pack donkeys at a Meru County health clinic. She presented their results at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

Performing Endoscopy in Working Donkeys

The team used an endoscope to evaluate each donkey’s trachea, and blinded reviewers evaluated the videos to grade tracheal collapse and identify tracheal ring abnormalities. The researchers also noted the presence of ventral neck skin and hair abnormalities on physical examination, which could indicate an improperly fitted harness.

Although performing an endoscopy on donkeys is more technically challenging than in horses, Mellish reported being able to grade tracheas with an average of 21 seconds of endoscopic video of the trachea. In total they reviewed 80 videos and recorded that 66 were considered diagnostic—38 from cart donkeys and 28 from pack donkeys. They considered some videos to be nondiagnostic if mucous obscured the camera lens or they could not pass the scope deep enough into the trachea.

Investigating the Effects of Harness Placement in Working Donkeys

The video reviewers identified a high prevalence of Grade 3 tracheal collapse—where the diameter of the trachea is reduced by 50% to 75%—occurring in almost 40% of the cart donkeys. They did not diagnose any cart donkeys with Grade 4 (full) tracheal collapse. In contrast, no pack donkeys had Grade 3 or 4 tracheal collapse.

“We also found a strong association between tracheal collapse and tracheal ring abnormalities and pulling carts,” said Mellish. “It is possible that the repeated trauma to the cervical trachea caused the endoscopic findings.”

These tracheal abnormalities, she said, are a significant welfare concern; affected donkeys might struggle to breathe, have low oxygen levels, or be reluctant to work. This in turn might result in prodding or maltreatment from the driver.

In addition, two-thirds of the cart donkeys had hair loss and thickened skin on the ventral neck, which was positively associated with tracheal collapse.

Take-Home Message

Mellish and her team found that 40% of cart donkeys experienced a significant reduction in trachea size, which has a direct impact on the animals’ welfare. However, they did not observe the tracheal changes in pack donkeys. “These findings are a foothold for improving harness and cart design to improve welfare in this community,” she said.

Bisphosphonates are drugs that inhibit bone breakdown and resorption, and a common treat­ment for bone disorders such as podo­trochlosis (navicular). They are FDA-approved for use in horses 4 and older.

Vets should not administer bisphos­phonates less than 28 days prior to recognized competitions. When selecting cases, consider the horse’s age, reason for treatment, and additional non-steroidal anti-inflammatory (NSAID) use, said Lindsey Boone, DVM, PhD, Dipl. ACVS-LA, associate professor of equine surgery and sports medicine at Auburn Univer­sity’s College of Veterinary Medicine, in Alabama. She spoke on the subject in a Sunrise Session at the 2024 American As­sociation of Equine Practitioners Conven­tion, held Dec. 7-11, in Orlando, Florida.

How Safe Are Bisphosphonates?

To test safety in horses, scientists evaluated the drugs at one, two, and three times the label dose and saw no bone density changes, meaning they’re very safe at the label dose, said Greg Schmid, DVM, equine professional services vet at Dechra. In young horses at one, two, and four doses, they saw no growth parameter changes but a mild metabolic parameter increase after two doses. “They also did not observe any negative effects on the horses’ skeletal health,” he added.

In horses presenting with acute kidney injury after bisphosphonate treatment, scientists found 75% were also given NSAIDs, had a poor appetite, abnormal urination, weight loss, and colic, said Boone. “Most responded positively to IV fluids and made a full recovery,” she said. She advised stopping NSAIDs prior to treatment to reduce renal injury risk.

Because bisphosphonates can lead to brittle bones in humans, researchers examined their long-term effects (up to one year) on equine bone remodeling. They found long-term repeat administration had a limited effect on remodeling over 12 months. Patient selection and pathology (disease or damage) are important considerations when choosing to treat with a bisphosphonate, said Boone.

Bisphosphonate Case Studies

A 5-year-old show jumper became acutely lame with no obvious abnormalities, but nerve blocks pointed to the fetlock. After a CT scan revealed joint injury, vets performed surgery, then bisphosphonate, interleukin-1 receptor antagonist protein, and intra-articular (IA) bone- marrow-derived stem cell injections, said Sarah le Jeune, DVM, CVA, Cert. Vet Chiro, Dipl. ACVS, ACVSMR, professor of surgical and radiological sciences at the University of California, Davis. “At his two-year postop checkup he had returned to some level of jumping, but a lower level than … capable of prior to the injury.”

A 9-year-old dressage horse presented acutely 4/5 lame with only mild improvement after a palmar digital nerve block but significantly improved after an abaxial sesamoid nerve block. Hoof and fetlock X rays showed no abnormalities. Vets treated him conservatively with “multiple bisphosphonate injections, IA platelet-rich plasma, shock wave, and rest, but he showed no improvement after one year,” said le Jeune.

A 5-year-old event horse was intermittently lame and painful on suspensory branch palpation. The ultrasound was unremarkable, but le Jeune treated with bisphosphonate injections, shock wave, and rest. He made a full recovery and returned to the same level of work.

Take-Home Message

Bisphosphonates are safe, but vets should not administer NSAIDs in con- junction with them and should check renal function via bloodwork during treatment. Also, if used off label (for anything besides navicular), bisphosphonates might be an effective part of a multimodal treatment approach for some musculoskeletal pathologies.

During the Dec. 8 Sunrise Session “Healing With Horsepower,” presented by Zoetis, at the 2024 American Association of Equine Practitioners (AAEP) Convention, a panel reviewed recent study results on autologous blood-based products and their effects on equine joints and metabolic parameters. 

APS—Disease-Modifying Effects?

Kyla Ortved, DVM, PhD, Dipl. ACVS, ACVSMR, associate professor of large animal surgery at University of Pennsylvania’s New Bolton Center, and colleagues investigated autologous protein solution’s (Pro-Stride^® APS) effects on synovial fluid parameters and joint pathology scores in 18 horses with induced synovitis. The goal was to identify intra-articular (IA) therapies vets can use to intervene early in the progression of joint disease.

While APS didn’t alter treated horses’ synovial fluid parameters or decrease lameness or joint circumference compared to controls, it significantly decreased gross pathology and synovial membrane histopathology scores when compared to the normal joint.

“APS may have disease-modifying effects within the synovium that could have significant, long-lasting downstream effects on the joint,” said Ortved.

In a second study Ortved compared four autologous blood-based devices: Alpha2EQ (alpha-2-macroglobulin, or A2M), Pro-Stride APS, Restigen^® PRP, and Arthrex ACP (autologous conditioned plasma). Her team sought to quantify A2M, immunomodulatory cytokines, and the growth factor TGFβ-1 for each in six healthy horses. They found APS had the highest A2M concentration and saw high concentrations of IL-1Ra, a potent anti-inflammatory cytokine, in APS and PRP but not the other products. They saw no significant differences between other cytokine levels in any products and found the highest concentration of TGFβ-1 in Restigen PRP, which she said isn’t surprising because it is high in platelets.

“This tells us that blood-based products do have different immunomodulatory and growth factor profiles, and that’s probably a reflection of the different concentration of platelets and white blood cells, and the different processing,” Ortved said.

APS and ACS Safe for PPID Horses 

Will pituitary pars intermedia dysfunction (PPID) affect orthobiologics’ anti-inflammatory and, thus, beneficial properties? Valerie Moorman, DVM, PhD, Dipl. ACVS-LA, clinical professor in the University of Georgia College of Veterinary Medicine’s Department of Large Animal Medicine, and team compared pro- and anti-inflammatory cytokine concentrations from six PPID and six non-PPID horses before and after processing blood for APS and autologous conditioned serum (ACS). They found no statistically significant cytokine differences in any groups, suggesting PPID does not alter ACS and APS cytokine profiles, so they could be effective in PPID horses.

APS Has No Metabolic Effects 

Intra-articular (IA) corticosteroids remain popular therapies for equine joint pain despite published research on their metabolic effects. Allen Page, DVM, PhD, assistant professor at the University of Kentucky’s Gluck Equine Research Center, and team recently investigated if orthobiologics could be a safer alternative.

They compared metabolic effects of IA triamcinolone acetonide (TA), APS, and a saline control on five metabolically normal horses and hypothesized that “compared to the saline and the Pro-Stride-treated groups, a single 9-milligram dose of IA triamcinolone will elicit changes in a variety of different parameters, including ACTH, cortisol, insulin, glucose, as well as some thyroid hormones,” said Page. “We also wanted to look at what the effects of those different treatments would be on the oral sugar test (OST) for insulin dysregulation and the thyrotropin-releasing hormone (TRH) test for PPID.”

They found TA had significant effects on ACTH, cortisol, glucose, and insulin levels; APS did not. They saw significant insulin increases even in normal horses. 

“Use intra-articular triamcinolone with caution in insulin-dysregulated horses due to induced hyperinsulinemia,” Page said. “Pro-Stride might be a safer alternative for insulin-dysregulated horses.” He urged vets to perform OST and TRH testing before injecting IA corticosteroids.

While pituitary pars intermedia dysfunction (PPID, formerly known as equine Cushing’s disease) and insulin dysregulation (ID, similar to human prediabetes) are two separate equine endocrine disorders, researchers estimate a 30% average comorbidity rate, meaning horses have both. Erica Macon, MS, PAS, PhD, assistant professor of equine science at Texas A&M University, in College Station, outlined the process of testing a horse for both conditions at the 2024 American Association of Equine Practitioners Convention, held Dec. 7-11, in Orlando, Florida.

What Do PPID and ID Look Like?

The phenotypes, or observable characteristics, of PPID and ID are distinct from one another, Macon said:

• For PPID, veterinarians and horse owners most often notice muscle atrophy (wasting), hypertrichosis (a long, curly coat), patchy shedding, and retained hairs.
• As for ID, they are more likely to note generalized obesity, regional fat deposits (i.e., cresty neck), and chronic or subclinical laminitis as visible—but not pathognomonic (exclusive)—indicators of the condition.

“Appearances can be deceiving, as both lean and fat horses can have neither, either, or both conditions,” Macon explained. “I have seen a morbidly obese—body condition score 9/9 on the Henneke scale—horse with regional fat deposits with insulin levels in the healthy range.” While PPID mainly affects horses 15 or older, the younger equine population is not immune. As for ID, horses of any age, sex, or breed can be affected, although overweight horses and certain breeds (such as Warmbloods and pony breeds) are predisposed.

Equine Endocrine Disorders: Diagnostic Testing for ID in Horses

Macon cautioned horse owners and practitioners against relying on resting insulin levels to diagnose ID because this number can fluctuate based on feeding status (such as a recent grain meal) and seasonality. Additionally, some ID-affected horses have normal resting insulin concentrations, creating a false negative result.

Experts now agree the oral sugar test (OST) is a better alternative. Macon reviewed the proper steps to perform this diagnostic screening:

1. Withhold grain for five to six hours before testing.
2. Administer a 0.15 mL/kg body weight dose of corn syrup (e.g., Karo syrup), which is very rich in sugar. Include an extra 5 mL to account for spillage.
3. Draw blood (in a ethylenediaminetetraacetic acid, EDTA tube, which prevents clotting and preserves cells) 60 minutes after administration.
4. Check results. Blood insulin levels over 45 µIU/mL indicate ID.

Equine Endocrine Disorders: Diagnostic Testing for PPID in Horses

Veterinarians have long considered measuring resting ACTH levels the standard for diagnosing PPID in horses. Because stress, geographical region, and seasonal variations can skew results, practitioners have instead turned to the thyrotropin-releasing hormone (TRH, also called thyroid-releasing hormone) stimulation test, which Macon detailed:

1. Draw blood in an EDTA blood tube.
2. Inject TRH. The dose will depend on body weight. Equids weighing less than 250 kg should receive 0.5 mg TRH, and those weighing more than 250 kg should receive 1.0 mg TRH.
3. After TRH administration wait 10 minutes and take another blood sample.
4. Check results: 100-200npicograms/mL is suspect, and over 200 pg/mL is likely indicative of PPID.

Comorbidities: ID and PPID in Horses

When veterinarians suspect a horse might have both PPID and ID, the tests remain the same as they would for diagnosing either disorder separately. If testing for both endocrine diseases on the same day, Macon suggests performing the TRH test first, followed by the OST. Conducting the OST before the TRH stimulation test could result in a false positive.

Take-Home Message

Diagnosing equine endocrine disorders involves carefully evaluating clinical signs, following test protocols, and considering confounding factors. “Each endocrine case will present and react differently,” Macon said. By keeping these guidelines in mind, veterinarians can accurately diagnose and manage PPID or ID—or both—in their equine patients.

Katie Sheats, DVM, PhD, Dipl. ACVIM, FHEA, associate professor of equine primary care at North Carolina State University’s College of Veterinary Medicine, in Raleigh, received the American Association of Equine Practitioners (AAEP) 2024 Distinguished Educator–Academic Award for her innovative leadership that is transforming the education and training of veterinary students. 

The Distinguished Educator–Academic Award recognizes an individual who by her or his actions and commitment has demonstrated a significant impact on the development and training of equine practitioners. Sheats accepted her award Dec. 10 during the President’s Luncheon at the 70^th Annual AAEP Convention, held in Orlando, Florida.

Sheats received her veterinary degree in 2005 from North Carolina State University, where she subsequently completed a rotating equine internship, equine internal medicine residency, and PhD in comparative biomedical science. She joined the university faculty as assistant professor of equine primary care in 2014. In addition to her teaching duties, she runs a successful lab and has served as primary advisor and committee member for numerous graduate students. 

As leader of the Equine Primary Care rotation, Sheats developed the school’s first formal distributive clinical education program. She partnered with local and regional practices to create an introductory “boot camp” to ensure participating students are prepared for what they will encounter in the field upon graduation, and she developed training and evaluation materials to support the partner practices in providing educational opportunities and feedback to the students. 

As co-coordinator for the third-year Equine Medicine and Surgery Course, Sheats has updated numerous lectures to focus more on equine primary care and introduced active learning methods to encourage in-person class attendance. Sheats has also created two new equine courses, one of which teaches unique aspects of husbandry and nutrition for less familiar species such as horses. 

Sheats is also coordinator for a new third-year preceptorship that provides a four-week experience in a veterinary practice or workplace setting to give students added clinical and real-world experience that reinforces core medical and surgical courses and prepares students for clinics and future careers. In addition, she teaches numerous lunch sessions on equine veterinary topics, and she regularly engages students with wet labs by taking first-, second-, and third-year students on weekend farm calls for authentic experiential learning in equine primary care. 

“Dr. Sheats is an innovator and master educator whose research and work in veterinary education and curricular development has and will continue to shape the way that we train equine veterinarians at NC State,” said her nominator, Anthony Blikslager, DVM, PhD, Dipl. ACVS, AGAF.

The American Association of Equine Practitioners (AAEP) presented its 2024 Distinguished Service Award to Bruce Whittle, DVM, owner of Honey Creek Veterinary Hospital, in Trenton, Missouri, for his longstanding leadership of the AAEP’s Essential Skills Workshops for students and his staunch advocacy on veterinary scope-of-practice issues. 

The Distinguished Service Award honors exemplary service to the AAEP or a similar organization to the benefit of the horse, horse industry, or profession of equine veterinary medicine. Whittle received his award Dec. 10 during the President’s Luncheon at the AAEP’s 70th Annual Convention, in Orlando, Florida.

Whittle is the longtime linchpin of the AAEP’s Essential Skills Workshop in dentistry, an immersive weekend program begun in 2009 and offered approximately 20 times each academic year for AAEP student chapter members at veterinary schools across North America. Since its inception, Whittle has served as an instructor at 45 different workshops at 24 colleges of veterinary medicine. He additionally recruits AAEP members to serve as volunteer workshop instructors; coordinates with local faculty to make live horses and cadaver heads available for student training; and regularly reviews and updates the workshop curriculum so that student education is rooted in sound primary care practices. 

“Since its beginnings in 2009, Dr. Whittle has truly been the ‘captain’ of the AAEP volunteer team who makes this program a reality,” said co-nominator Kenton Morgan, DVM. “Through his efforts, Dr. Whittle has personally helped educate hundreds of veterinary students in the art and science of equine dentistry, directly impacting the health and welfare of horses and the profession of equine veterinary medicine.” 

Beyond his deep-seated commitment to veterinary students, Whittle has championed the horse and profession through his volunteer service with the AAEP and Missouri Veterinary Medical Association (MVMA), particularly on public policy and scope of practice issues. He has been directly involved in state-level legislative action to deregulate equine dentistry, and he has personally educated veterinary medical associations about the potential negative professional, ethical, and health-care effects of unlicensed veterinary practices. In conjunction, he directly participated in crafting AAEP position statements on Dentistry, Levels of Supervision, Practice of Veterinary Medicine, and Roles of Healthcare Providers in Veterinary Medicine. 

Whittle, who received his veterinary degree in 1994 from the University of Missouri, in Columbia, is a past president of the MVMA and a former chair of the AAEP’s Welfare and Public Policy Advisory Council. 

The American Association of Equine Practitioners (AAEP) presented its 2024 AAEP Research Award to Noah Cohen, VMD, MPH, PhD, Dipl. ACVIM, for his recent research into equine strangles and Rhodococcus equi pneumonia that has resulted in significant advances in understanding the pathophysiology, diagnosis, and treatment of these diseases.  

The AAEP Research Award recognizes an individual who has completed research that has or will make a significant impact on the diagnosis, treatment, or prevention of equine disease. Cohen accepted his award Dec. 10 during the President’s Luncheon at the AAEP’s 70th Annual Convention, in Orlando, Florida. 

Cohen is a distinguished professor and associate department head of large animal clinical sciences at Texas A&M University’s School of Veterinary Medicine and Biomedical Sciences, in College Station. Throughout his career he has authored or coauthored 293 papers and 35 review articles in refereed journals. His recent research involves the pathophysiology of R. equi, including detection, risk factors, antibiotic resistance, hyperimmune plasma treatment, and use of an RNA (ribonucleic acid) vaccine. He has also completed research on Streptococcus strains in horses (the bacterium S. equi subspecies equi causes strangles).

Cohen’s co-nominators Nathaniel White, DVM, MS, Dipl. ACVS; Bill Moyer, DVM; and C. Wayne McIlwraith, DVM, Dipl. ACVS, ECVS, ACVSMR, wrote that “both diseases represent significant morbidity with a negative economic impact on the horse industry. Dr. Cohen’s recent inventions include a serological test for strangles and an RNA vaccine for Rhodococcus foal pneumonia both in the past two years.”

Cohen received his veterinary degree from the University of Pennsylvania, in Philadelphia, in 1983. After two years in private equine practice, he completed MPH and PhD degrees in epidemiology at Johns Hopkins University, in Baltimore, followed by a large animal internal medicine residency at Texas A&M. He joined the Texas A&M faculty as an assistant professor of equine medicine in 1991. 

Cohen has served on the AAEP’s Infectious Disease and Research committees, and he delivered the Frank J. Milne State-of-the-Art Lecture on the topic of equine epidemiology at the 2011 AAEP Annual Convention. His numerous other accolades include the 2002 John Hickman Memorial Lecture at the British Equine Veterinary Association Congress, 2008 Schering-Plough Applied Equine Research Award, 2015 Zoetis Award for Excellence in Research, and 2019 AVMA Clinical Research Award.

Sara Langsam, VMD, chair of the American Association of Equine Practitioners’ (AAEP’s) Racing Committee received the President’s Award Dec. 10 during the AAEP’s 70th Annual Convention, in Orlando, Florida. Langsam has spearheaded AAEP’s efforts to address the issue of catastrophic musculoskeletal injuries in Thoroughbred racehorses, going beyond established risk assessment protocols.

The President’s Award recipient is selected by the sitting AAEP president and honors an AAEP member who has demonstrated a dedication to the association during the past year by contributing significant time and expertise to benefit the health and welfare of the horse. 

Langsam, partner at South-Florida-headquartered Teigland, Franklin, and Brokken DVMs, Inc. (TFB Equine), and manager of its Belmont Park division, coordinated a Thoroughbred safety and injury prevention summit meeting of veterinary experts in October 2023. Among the recommendations to emerge was an ambitious and potentially transformational yearlong project to begin in January 2025 under Langsam’s oversight to evaluate the suitability of six wearable biometric sensors for widespread use in initial screening of the U.S. Thoroughbred racing and training population. The goal is early identification of horses at risk for musculoskeletal injury.

“Getting this project from idea to reality has been a Herculean task, involving defining the parameters of the research project, securing funding, communicating with the companies involved, navigating complex politics, facilitating the logistical details, and so much more,” said Katie Garrett, DVM, Dipl. ACVS, 2024 AAEP president, during the award presentation at the President’s Luncheon.  

“Dr. Langsam has done all of this, while also finding time to coordinate initiatives like the incredibly successful ‘Day at the Races’ program, which brings veterinary students to racetracks so they can learn about veterinary careers in the racing industry,” Garrett added. “She is also a full-time practitioner and serves on the AAEP’s board of directors, so how much she has achieved this year is truly remarkable.”

After receiving her veterinary degree from the University of Pennsylvania, in Philadelphia, in 2002, Langsam completed an in-hospital internship at Rood & Riddle Equine Hospital in Lexington, Kentucky. She joined TFB Equine in July 2003, became a partner in 2009, and in 2012 expanded the practice to provide year-round services for its clients at Belmont Park in Elmont, New York. 

Langsam serves as an AAEP on call veterinary spokesperson in support of live telecasts of Thoroughbred racing. She previously served on the Educational Programs Committee and Professional Conduct and Ethics Committee. Beyond the AAEP, Langsam is a member of the Horsemen’s Advisory Group of the Horseracing Integrity and Safety Authority.

Tom Riddle, DVM, renowned authority on equine reproduction and the retired co-founder of Rood & Riddle Equine Hospital in Lexington, Kentucky, received the 2024 Distinguished Educator–Mentor Award from the American Association of Equine Practitioners (AAEP).

The Distinguished Educator–Mentor Award honors an individual who by her or his actions and commitment has demonstrated a significant impact on the development and training of equine practitioners through mentoring. Riddle received his award Dec. 10 during the President’s Luncheon at the AAEP’s 70th Annual Convention, in Orlando, Florida.

After receiving his veterinary degree from the University of Georgia in 1978, Riddle spent four years at Spendthrift Farm, in Lexington, Kentucky, before joining Bill Rood, DVM, in his ambulatory practice to form Rood & Riddle in 1982. Three years later the pair broke ground on their landmark hospital, and the practice has grown exponentially since. 

Through his dedication to teaching and mentoring, Riddle has profoundly influenced and helped shape the careers of veterinary interns and others who have come through the practice. As a result of his guidance, many of Riddle’s interns went on to complete theriogenology (the study of animal reproduction) residencies, attain board certification, and ultimately become influential mentors themselves. 

“The consequence of Dr. Riddle’s mentorship has had a trickle-down effect,” said co-nominator Virginia Reed, DVM, “creating generations of skilled, enthusiastic equine veterinarians ready and willing to mentor other veterinarians throughout their careers.”

In addition, Riddle has spearheaded immersive continuing-education events on equine reproduction, including a low-cost symposium where theriogenology residents gain hands-on skills with guidance from established theriogenologists. 

“Dr. Riddle’s guidance and support have shaped the careers of so many veterinarians,” added co-nominator Meghan Connor, DVM. “His ability to provide leadership while allowing the personal and professional growth of his mentee is unmatched. His upstanding morals and dedication to honesty instilled great ethics that have stayed with me into many aspects of veterinary practice.”

Tracy Turner, DVM, MS, Dipl. ACVS, ACVSMR, partner in Turner Wilson Equine Consulting, in Stillwater, Minnesota, became president of the American Association of Equine Practitioners (AAEP) on Dec. 10. He was installed during the President’s Luncheon at the 70^th Annual AAEP Convention, held in Orlando, Florida.

Turner retired from private practice in December 2023 after concentrating exclusively on equine sports medicine, lameness, and surgery at his Turner Equine Sports Medicine and Surgery. He established the practice in 2016 following 12 years with Anoka Equine Veterinary Services in Elk River, Minnesota. He joined Anoka Equine after 23 years in academia as an assistant professor at the University of Illinois, in Urbana (1981–1983), tenured associate professor at the University of Florida, in Gainesville (1983–1990), and tenured professor at the University of Minnesota, in Minneapolis (1991–2004). Turner received his veterinary degree from Colorado State University, in Fort Collins, in 1978. 

He has consulted for the USDA Horse Protection Program, Fédération Equestre Internationale, the United States Equestrian Federation, and the American Quarter Horse Association. Turner also delivers medical care to working equids and education to students and caretakers in Central America as a volunteer with the Equitarian Initiative, cofounded by his wife, Julie Wilson, DVM. 

An AAEP member since 1986, Turner previously served on the organization’s board of directors from 2017 to 2019; as chair of the Farrier Liaison Committee; and as member of the Educational Programs and Student Relations committees as well as the Foundation Advisory Council. He was instrumental in creating the AAEP student chapter veterinary podiatry workshops in the early 1990s, and he served as the faculty advisor for the AAEP student chapter at the University of Minnesota for many years. 

Beyond the AAEP, Turner has served as president of the Minnesota Horse Council, Minnesota Association of Equine Practitioners, and the American Academy of Thermology; and on the board of directors of the American Academy of Equine Sports Medicine. In addition, he has authored more than 110 refereed manuscripts and 31 book chapters, and he has delivered hundreds of presentations throughout the United States and internationally.