Gastric Ulcer Syndrome Common Cause of Poor Performance

Appropriate preventive and therapeutic measures to avoid and/or treat gastric ulcers in endurance horses might improve performance.

Equine gastric ulcer syndrome (EGUS) is extremely common in competitive horses involved in show jumping, dressage, and Western disciplines. One recent study reported that more than 90% of racehorses had EGUS.

"Unlike these other types of athletic horses, the prevalence of gastric ulcers in endurance horses is less well-studied. One group found that two-thirds of horses examined after a 50 or 80 km endurance ride had gastric ulcers, but no data on horses competing at higher levels (i.e., 90-160 km) are currently available," said Youssef Tamzali, DVM, PhD, Dipl. ECEIM, of the Ecole Veterinaire de Toulouse (National Veterinary School) in France.

Tamzali and his research team, therefore, performed two separate gastroscopes in 30 high-level endurance horses: one during the off-season period and the second during the competition season within 2-3 days of competing in a 90-160 km ride.

Key study findings were that 48% of the horses had gastric ulcers during the off-season period, and 93% of the horses had gastric ulcers during the competition season. This difference was statistically significant, and age, breed, and gender did not influence the results.

"This high prevalence of gastric ulcers in elite endurance horses is similar to the rates of ulcers in other athletic horses and could be an important cause of poor performance," relayed Tamzali.

Two other important findings Tamzali uncovered were:

  1. Horses kept on pasture showed significantly higher "ulcer scores" than the horses housed in a mixed environment (the group of horses kept on pasture had a high starch diet due to added concentrates); and
  2. A positive correlation existed between "gastric score" severity and ride distance: the longer the ride, the more severe the score.

"These results strengthen those obtained by another research group and underline the fact that amount of starch fed per day or per meal is a very important factor in development of ulcers," added Tamzali.

The study, "Prevalence of gastric ulcer syndrome in high-level endurance horses," will be published in an upcoming edition of the Equine Veterinary Journal. The abstract is available online.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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