Equine gastric ulcer syndrome (EGUS) affects the majority of horses in active training, causing chronic pain that impairs performance and welfare in often-unrecognised ways.
EGUS causes chronic abdominal pain in the majority of sport horses that goes largely unrecognised because the signs — poor performance, reluctance to work, changed temperament, and girthing resentment — are attributed to behavioural or training issues rather than pain. Horses with EGUS are working through pain in most performance situations, representing a widespread but underappreciated welfare problem in equestrian sport. The high prevalence reflects management practices that conflict with horses' evolved physiology — long periods without forage, intensive training, and competition stress. Management changes that allow continuous forage access, reduce stressors, and provide appropriate medication represent a major welfare improvement.