Horse Gastric Ulcer Syndrome: Welfare and Prevention

Equine gastric ulcer syndrome is extremely prevalent in horses and causes significant pain and welfare impact across all disciplines.

Key Facts

Studies estimate 60-90% of performance horses and 37% of leisure horses have gastric ulcers
The horse's stomach produces acid continuously but is protected only when eating fibrous feed
Periods without feed — common in stabled horses — expose the non-glandular stomach to acid damage
Signs include poor body condition, reduced performance, crib-biting, and altered behaviour under saddle
Omeprazole is the gold standard treatment — effective within 28 days in most horses
Prevention centres on maximising forage access and minimising periods of gastric emptiness

Welfare Considerations

Gastric ulcers cause genuine, chronic pain that affects a horse's every interaction with its environment and handler. Horses with active ulcers may be incorrectly labelled as difficult, resistant, or lazy when their behaviour reflects pain rather than willingness problems. Welfare-centred management prevents ulcers through dietary management — ensuring horses never go more than 4 hours without forage, using haylage or chaff to buffer acid during competition, and reducing starchy concentrate feeds. Treatment is straightforward when diagnosed correctly. The high prevalence of gastric ulcers reflects management practices that are convenient for humans but incompatible with the horse's gastric physiology.

What You Can Do

Ensure stabled horses always have forage available — never leave horses with empty stomachs for more than 4 hours
Feed a small forage portion before exercise to buffer stomach acid
Consult your vet if your horse shows unexplained behaviour changes, poor condition, or reluctance under saddle
Consider gastroscopy for horses in intensive training — early diagnosis improves outcomes
Manage stress in training programmes — cortisol increases gastric acid production