Gastric ulcers affect over 60% of performance horses and cause chronic pain. Evidence-based management including omeprazole treatment, dietary change, and management modification significantly improves welfare.
EGUS is a pervasive welfare problem in performance and leisure horses. The equine stomach produces acid continuously, unlike humans who secrete acid primarily in response to food. When horses are stabled for extended periods without forage access, unbuffered gastric acid erodes the squamous stomach lining, causing painful ulcers. The behavioral signs — girthiness, poor performance, reluctance to work, and behavioral changes — often prompt training changes rather than medical investigation.
Pain from gastric ulcers is chronic and insidious. Horses cannot communicate pain verbally, and subclinical discomfort during training, tacking up, and work affects their training responsiveness and welfare without being identified as pain-related. Validated EGUS behavioral grading tools help identify horses likely to have ulcers based on behavioral presentation.
Omeprazole treatment over 28 days heals most ulcers reliably. However, recurrence is common if management is not changed. Prevention — through continuous forage access, reduced concentrated feeding, minimizing travel and competition stress, and pasture turnout — addresses root causes rather than repeatedly treating the consequences. Hay or haylage available through the night dramatically reduces overnight gastric acidification.