Gastric ulcer development in horses in a simulated show or training environment.

Objective: To determine whether conditions representing activities that are typical in the recreational use of horses, including transport to and from show grounds, stall confinement in unfamiliar surroundings, and light exercise, are associated with increased incidence of gastric ulcers in horses.

Design: Randomized controlled study.

Animals: 20 client-owned horses.

Procedure: Horses had no gastric ulcers as determined by endoscopic examination on study day -1. Ten control horses were maintained on-site with no changes in management variables. Ten horses were transported via trailer for 4 hours on day 0 to another site, placed in individual stalls, fed twice daily, and exercised twice daily for 3 days. On day 4, they were transported back to the original site via trailer for 4 hours. On day 5, endoscopic examinations were performed on all horses to assess gastric mucosa status.

Results: Horses that were transported and housed off-site had a significantly higher incidence of hyperkeratosis and reddening of the gastric mucosa than control horses. Two control horses and 7 transported horses developed gastric ulcers by day 5. Ulcer scores of transported horses increased significantly from day -1, whereas ulcer scores in control horses did not change significantly from day -1.

Conclusions And Clinical Relevance: Activities that are typical in recreational use of horses were ulcerogenic, and ulcers in the gastric squamous mucosa can develop under these conditions within 6 days.