Equine gastric ulcer syndrome affects the majority of performance horses and many leisure horses, causing chronic pain that significantly impairs welfare and often goes undiagnosed.
Gastric ulcers in horses represent a welfare problem created almost entirely by management systems that conflict with equine physiology. Horses evolved to graze continuously; their stomach produces acid constantly; and an empty stomach between meals means acid burns unprotected squamous epithelium in the upper stomach. The pain is chronic and cumulative — horses living with active ulcers experience persistent discomfort that affects behavior, performance, and quality of life. The dramatic improvement in ulcer prevalence achievable through simple management changes — more forage, less grain, more turnout — represents a high-leverage, low-technology welfare intervention.