Equine Gastric Ulcer Syndrome Welfare

Equine gastric ulcer syndrome (EGUS) affects the majority of performance horses, causing chronic abdominal pain that significantly impacts welfare and is often missed or misattributed.

Key Facts

Gastric ulcers affect up to 90% of racehorses, 60% of performance horses, and 30% of leisure horses
Horses evolved to graze continuously — their stomachs produce acid constantly, and long periods without forage allow acid to damage the stomach lining
Clinical signs are often vague and behavioral: girthiness, reluctance to work, poor performance, teeth grinding, and mild colic
Squamous ulcers (upper stomach) are most common in performance horses; glandular ulcers (lower stomach) are harder to treat
Omeprazole (GastroGard) effectively treats squamous EGUS; glandular ulcers may require sucralfate and misoprostol in addition
Stress, NSAIDs (bute), high-starch diets, and stabling without constant forage access are primary risk factors
Horses on pasture with ad libitum grass access have dramatically lower ulcer prevalence than stabled horses

Welfare Considerations

Gastric ulcers cause chronic, often severe pain that horses mask — they are stoic prey animals who do not show pain overtly until it becomes extreme. A horse that pins its ears when girthed, bucks when first asked to canter, or shows poor performance may be experiencing daily abdominal pain from active ulceration. The prevalence is staggering — the majority of stabled, working horses are affected to some degree. Management changes are highly effective and relatively simple: ad libitum forage access (hay or chaff to buffer stomach acid), turnout time, minimizing NSAID use, reducing high-starch concentrate feeding, and providing hay before exercise. Treatment with omeprazole heals squamous ulcers reliably within 28 days. Welfare improvement requires that trainers and owners recognize behavioral signs of pain as signals, not training problems.

What You Can Do

Provide constant forage access — never leave horses without hay for more than 2-3 hours, especially at night
Ensure horses receive hay before exercise — foraging before work protects the stomach from acid splash
Consult your vet if your horse shows girthiness, poor performance, or behavioral changes — request gastroscopy for definitive diagnosis
Minimize NSAID use and consult your vet about gastric protection when NSAIDs are necessary
Increase turnout and reduce stabling duration wherever possible — pasture access is the single best ulcer preventive