Horse Gastric Ulcer Prevention and Welfare

Equine gastric ulcer syndrome affects the majority of performance horses, causing chronic pain that impairs welfare, behavior, and performance — yet remains underdiagnosed in most populations.

Key Facts

Equine Squamous Gastric Disease affects approximately 60-80% of racehorses and 40-60% of sport horses in active work
Horses evolved to graze continuously — their stomachs produce acid continuously regardless of food availability
The squamous (upper) stomach lacks protective mucus and is vulnerable to acid splash during exercise
Behavioral indicators of gastric ulcers include poor appetite, girthiness, behavioral changes, and reduced performance
Omeprazole (GastroGard) is the gold standard treatment and provides rapid symptom relief within days
Feeding hay before exercise reduces acid splash by providing a physical buffer and stimulating bicarbonate secretion
Alfalfa hay has higher buffering capacity than grass hay and may reduce ulcer risk when fed appropriately

Welfare Considerations

Equine gastric ulcer syndrome causes chronic acid discomfort affecting a majority of actively worked horses — one of the most common and undertreated welfare problems in equine medicine. Horses cannot communicate stomach pain verbally, and the behavioral indicators — mild girthiness, variable appetite, altered behavior — are frequently attributed to training issues rather than medical cause. Many horses with significant ulceration grade 3 or 4 show relatively few clinical signs, masking the welfare impact. Management causes are well-understood: periods without forage, high-concentrate diets, transport stress, and intense exercise all contribute. Prevention is highly effective — continuous forage access, hay before exercise, and reduced concentrate proportion dramatically reduce ulcer risk and welfare harm. Treatment with omeprazole is effective but expensive, and economic pressure sometimes delays treatment in affected horses.

What You Can Do

Provide continuous forage access — horses should never go more than 4-6 hours without hay or pasture
Feed a small hay portion before exercise to reduce acid splash during work
Minimize concentrate proportion of the diet — high-forage diets reduce ulcer risk
Investigate gastric ulcers as a potential cause when horses show poor performance, behavioral changes, or girthiness
Request gastroscopy for definitive ulcer diagnosis rather than treating empirically without confirmation
Follow complete treatment protocols — stopping treatment early when symptoms improve leads to rapid recurrence
Manage transport and competition stress through pre-loading with forage and minimizing unnecessary travel