Gastric ulcer is characterized by damage to the lining of the stomach of the horse. The horse has the distinction of producing hydrochloric acid, on prolonged contact with the mucous membrane causes a breach thereof. Ulcers are often asymptomatic in the horse and they get a huge proportion of equines. The external factors like food, stress, transport, competition increases the risk of developing ulcers. n severe cases of ulcers, the horse after this refusal to eat, and colic which can be serious. The diagnosis is made with a gastroscopy.