Gastric ulcers affect the majority of performance horses and represent a widespread welfare problem linked to modern management and training practices.
Gastric ulcers in performance horses are largely a disease of management rather than of inherent biological vulnerability. The horse digestive system evolved for near-continuous low-level grazing, producing acid constantly that is buffered by saliva stimulated during chewing. When horses are managed with restricted hay access and large concentrate meals to support performance, the stomach acid is unbuffered for extended periods, causing progressive mucosal damage. The discomfort of ulcers affects behaviour, willingness to work, and quality of life. The irony is that the management practices that cause ulcers — restricted forage, high concentrate feeds, intensive training schedules, frequent transport — are adopted to enhance performance, yet the resulting welfare compromise undermines the very performance they are meant to support.