Gastric Ulcers Negatively Affect Athletic Performance in Horses, Report Says

Gastric ulcers have been blamed for poor performance in athletic horses for years, though definitive data supporting this contention is difficult to find. Using client-owned Standardbred racehorses, an Italian group of veterinary researchers demonstrated for the first time that equine gastric ulcer syndrome, or EGUS, has a negative effect on performance.^*

In the study, 87 Standardbred racehorses presenting with “poor performance” underwent full physical examinations, including gastroscopy to visualize the stomach lining and assign an EGUS grade. This grade included both squamous ulcers in the upper region of the stomach and glandular ulcers in the lower region. Incremental treadmill testing was then conducted, and various fitness parameters were recorded. These included speed at a heart rate of 200 beats/minute (V200), and the speed and heart rate when blood lactate levels reached 4 mmol/L (VLa4), among others.

Squamous ulcers were diagnosed in 99% of the included horses, with most of those horses diagnosed with severe disease. The prevalence of glandular ulcers was 53%. All horses with glandular ulcers had concomitant squamous ulcers.

V200 and VLa4 were both lower in horses with a higher EGUS score, reflecting an impairment of aerobic capacity.

“This is the first study to objectively measure fitness parameters in horses with naturally occurring EGUS. Previously, most studies evaluating the effect of EGUS on performance relied on trainer expectations for performance evaluation,” explained Ashley Fowler, Ph.D., a nutritionist for Kentucky Equine Research.

While extremely valuable from a clinical viewpoint, these data do not provide any information regarding the mechanisms by which EGUS negatively influences performance.

“Some proposed mechanisms include abdominal pain and decreased energy intake due to poor appetite,” Fowler explained.

Because squamous and glandular gastric disease are two different entities, current methods recommended for controlling EGUS in athletic horses differ based on the location of the ulcer.

Squamous ulcers (equine squamous gastric disease, ESGD): feeding large meals that include high amounts of nonstructural carbohydrates and stress are two risk factors for ESGD. Offering several smaller meals per day and treating with omeprazole, with or without sucralfate, are currently recommended for treating and managing squamous disease.

Glandular ulcers (equine glandular gastric disease, EGGD): risk factors for this form of EGUS include training frequency and intensity. Decreased training days may help improve EGGD, and misoprostol or a combination of sucralfate and omeprazole successfully treats some ulcers.

Kentucky Equine Research maintains a roster of research-proven products to support gastric health.

^*Lo Feudo, C.M., L. Stucchi, B. Conturba, G. Stancari, E. Zucca, and F. Ferrucci. 2022. Equine Gastric Ulcer Syndrome affects fitness parameters in poorly performing Standardbred racehorses. Frontiers in Veterinary Science 9:1014619.