Effect of Gastric Ulcers on Performance of Horses in Race Training

Gastric ulceration is common among horses that are stabled most of the time or are in a race training program. Various studies have shown that an average of 60 to 90% of horses in race training have a degree of gastric ulceration. Some horses with gastric ulcers tend to back off their feed, exhibit signs of mild colic, and develop a sour attitude toward work.

A recent study was designed to look at the effect of gastric ulcers on performance and body condition score in a group of 40 Standardbred horses in training. The horses were kept at two racing facilities in Michigan and ranged in age from 3 to 12.

All horses were examined with a gastroscope and received a gastric ulceration score from 0 to 4. A body condition score of 0 to 9 was also recorded, and each horse was given a performance score by its trainer, with A denoting excellent performance and F denoting poor performance.

Gastric ulcers were found in 50% of horses at one facility and in 56% of horses at the second facility. Ulcers were generally mild, with scores of 2 or higher in less than 20% of those with ulcers. Ulcer scores were not related to age, gender, performance history, or body condition score. Results of this study suggest that percentage of affected horses at racing facilities may be lower than previous indications, and that mild ulceration may have little effect on performance.

The study also indicated that endoscopic examination is the only accurate way to diagnose gastric ulceration, and showed no basis for assuming a horse has ulcers because it has lost weight or is performing poorly.