Gastric Ulcers in Horses: A Silent Epidemic

Equine gastric ulcer syndrome (EGUS) affects up to 90% of racehorses and 60% of performance horses, causing chronic pain that is often mistaken for behavioural or training problems.

Key Facts

Equine Squamous Gastric Disease (ESGD) affects the non-glandular upper stomach; Equine Glandular Gastric Disease (EGGD) affects the lower glandular region
Studies find gastric ulcers in 37-93% of horses depending on discipline and management — endurance, racing, and show horses most affected
Horses evolved to eat continuously — empty stomachs allow acid to splash onto the acid-sensitive squamous mucosa
Signs are often vague: poor performance, reluctance to work, girthiness, reduced appetite, and subtle behaviour changes
Definitive diagnosis requires gastroscopy (camera into the stomach under sedation)
Omeprazole (GastroGard/UlcerGard) is the gold standard treatment and prevention medication
Management changes — ad libitum hay, reduced starch, pasture access — are as important as medication
Without management changes, relapse rates after medication are extremely high

Welfare Considerations

Gastric ulcers represent a widespread, chronically painful, and chronically undertreated welfare problem in performance horses. The pain is real and measurable — horses with experimentally induced ulcers show elevated heart rates, behavioural avoidance, and altered facial pain expressions. Yet because horses work and eat through pain, ulcers are frequently missed. Veterinarians and trainers often encounter horses attributed as "difficult" or "resistant" who are in fact reacting to gastric pain. The management systems that cause ulcers — restricted forage, high-starch concentrates, intense exercise on empty stomachs, stress of competition and travel — are ubiquitous in performance horse management. Addressing EGUS requires both medical treatment and fundamental management change: the horse's digestive system evolved for continuous forage intake, not twice-daily feeding of energy-dense concentrates.

What You Can Do

Provide ad libitum or near-continuous access to good-quality hay or grazing — this is the single most protective management change
Reduce high-starch concentrate feeds and divide concentrates into multiple small meals
Consult your vet about prophylactic omeprazole during periods of intensive training, competition, or transport
If your horse shows performance reluctance, girthiness, or behaviour changes, request gastroscopy before assuming a training problem
Allow pasture access where possible — grazing is both physically and psychologically protective against ulcer development
Support EGUS research through equine welfare organisations