Induction and maintenance of gastric ulceration in horses in simulated race training.

This study looked at how simulated race training could induce and maintain gastric ulcers in horses. It also measured the horses’ serum cortisol levels to explore potential stress links to ulcer development. The research found that all horses experienced moderate to severe ulceration, maintained for eight weeks, indicating training conditions may indeed lead to ulcers.

Research Context and Objectives

• The research was instigated by the high incidence of gastric ulceration in racehorses. Previous studies have attempted to simulate and study this condition, but none have successfully replicated the specific conditions a racehorse undergoes during training. Thus, this study aimed to induce and maintain gastric ulcers in horses training under race-like conditions.
• Another facet of the research was to explore the role of stress in gastric ulcer development. To investigate this, the researchers measured the horses’ serum cortisol levels weekly – elevated cortisol is often associated with stress responses.

Methodology and Participants

• The study involved thirty horses undergoing simulated race training over eight weeks. They were fed Bermuda grass hay and a concentrated diet, and ran distances of 1.6 to 2.4 km at speed six days a week.
• Gastroendoscopic examinations were performed on a weekly basis, and serum was collected to measure cortisol levels. Importantly, none of the horses were given nonsteroidal anti-inflammatory drugs or experienced withholding of feed, conditions often present in other ulcer studies.

Results

• All horses developed moderate to severe gastric ulcers, and these ulcers were maintained for the entire eight-week period. Only one horse showed signs of abdominal discomfort, which was resolved with minimal treatment and without the use of anti-ulcer medications.
• In terms of the serum cortisol measurements, the levels stayed within the reference range for the duration of the study. However, there was a noticeable decrease from the initial measurements at the start of the study.

Conclusion and Implications

• The results suggest that the simulated race training conditions were successful in inducing and maintaining gastric ulcers in horses. Although the cortisol measurements did not suggest any significant stress response, the fact that ulcers developed in the conditions of this study provides a valuable model for future investigations.
• Such a model can further our understanding of gastric ulcers in racehorses, likely leading to improved preventive measures and treatment strategies. It could also be instrumental in investigating the effects of different medications on the healing of ulcers in these animals.