Horse Gastric Ulcer Syndrome: Prevalence, Pain, and Management

Equine gastric ulcer syndrome (EGUS) is an extremely common and painful condition in performance and companion horses, driven by management practices that conflict with equine physiology.

Key Facts

EGUS affects an estimated 60-90% of racehorses and 40-60% of performance horses.
Horses produce hydrochloric acid continuously; in the wild, near-continuous grazing buffers this acid.
Stabled horses fed twice daily have prolonged periods of unbuffered acid contact with the non-glandular squamous mucosa.
Signs include poor performance, reduced appetite, weight loss, and in severe cases behavioural changes indicating pain.
Omeprazole (GastroGard) is the gold-standard treatment; suppressing acid production allows ulcer healing over 28 days.

Welfare Considerations

EGUS causes significant chronic pain that is frequently underrecognised. The squamous (non-glandular) region of the equine stomach lacks protective mucosal secretions and is highly vulnerable to acid damage. Ulcers range from grade 1 (reddening) to grade 4 (deep ulceration with bleeding). Horses in pain may be labelled "difficult" and subjected to increased training pressure — a welfare compounding problem. The primary welfare solution is management reform: ad-libitum forage access, reduced stabling time, pre-exercise hay provision to create an acid buffer, and stress reduction. Omeprazole treatment without addressing underlying husbandry causes rapid relapse. Prophylactic treatment during periods of management change (transport, competition) is evidence-based welfare practice.

What You Can Do

Provide ad-libitum hay or equivalent forage access — this is the most important EGUS prevention measure.
Feed hay before exercise to create a gastric acid buffer.
Discuss omeprazole treatment and endoscopic monitoring with your equine vet.
Reduce stabling time and increase turnout where possible.
Support research into non-pharmaceutical EGUS management including dietary and management strategies.