Horse Gastric Ulcer Syndrome (EGUS) Welfare

Equine gastric ulcer syndrome affects the majority of performance horses and many leisure horses. Understanding its causes, signs, and treatment is essential for equine welfare.

Key Facts

Equine gastric ulcer syndrome (EGUS) encompasses squamous ulcers (ESGD) in the upper stomach and glandular ulcers (EGGD) in the lower stomach — distinct conditions with different causes and treatments
Prevalence is high: approximately 60–80% of performance horses and racehorses have evidence of squamous ulcers; glandular disease is increasingly recognised in sport horses
The horse's stomach produces acid continuously (unlike humans, who produce acid mainly when eating); without constant forage buffering this acid damages the squamous mucosa
Risk factors include high-grain, low-forage diets, intermittent feeding, intense exercise, NSAID use, transport stress, and stall confinement without social contact
Clinical signs are often subtle: reduced appetite, poor body condition, coat changes, reluctance to work, cinch sensitivity, and changes in behaviour or performance; some horses show colic
Diagnosis requires gastroscopy — direct visual examination of the stomach under sedation
Treatment with omeprazole (Gastrogard) is highly effective for squamous ulcers; glandular ulcers may require addition of sucralfate or misoprostol and are more difficult to resolve
Management changes — increased forage access, reduced starch intake, social contact, and reduced transport — are essential to prevent recurrence

Welfare Considerations

Gastric ulcers cause chronic discomfort and intermittent pain that significantly affects equine quality of life and willingness to work. The horse's continuous acid production means that any period without buffering forage creates an acidic environment that damages the stomach lining — a welfare problem inherent in management systems that restrict grazing and forage access. Horses in pain from ulcers show reduced performance and behaviour changes that are often attributed to training problems, leading to increased work pressure rather than investigation. The welfare priority is prevention through appropriate management: ad libitum forage access, reduced starch feeding, and minimising transport and social stress are all evidence-based preventive measures. Treatment is highly effective but recurrence without management change is common.

What You Can Do

Ensure horses have access to forage (hay or grazing) for the majority of the day and night — minimum 1.5% body weight in dry matter daily
Feed small, frequent hard feed meals rather than large, infrequent ones to reduce acid surges
If your horse shows performance reluctance, behaviour changes, or colic, request gastroscopy before assuming training issues
Administer omeprazole (Gastrogard) before periods of known high risk: transport, competition, dietary change
After ulcer treatment, address the management factors driving recurrence — treatment alone without management change typically results in relapse within weeks