Experts agree that everyday stressors can contribute to gastric ulcer formation in horses. All breeds and disciplines have been found to develop ulcers, sometimes in as little as five days.

An awareness campaign led by Merial sought to bring greater exposure to the issue of gastric ulceration in horses by hosting gastroscopy events across the country this past year.

In all, 658 horses from 25 states participated in events at veterinary clinics and university hospitals. About 60 percent—397 horses—had some ulceration evident during gastroscopy. Of those, 60 percent had grade 1 ulceration, which indicates mild ulcers with small lesions or damaged tissue.

Horses of various breeds and ranging from 1 to 41 years old were found to have gastric ulcers. In addition, ulcers were found both in horses kept in box stalls and those kept on pastures, and were evident regardless of whether horses were in training or rarely ridden.

Racing horses had the highest prevalence of ulcers—35 out of the 38 participating. Of the 17 reining horses evaluated, 13 had the condition. Show jumper and eventing horses didn't fare much better, with 67 percent (8 of 12) and 62 percent (28 of 45) showing ulceration, respectively.

The campaign also found that 254 horses in which gastric ulcers were diagnosed had no previous history of the condition. In addition, some horses fed supplements such as beet pulp, flaxseed oil, and corn oil still were identified with gastric ulcers.

According to a release issued by Merial, a number of triggers exist for gastric ulcer development. Horses are especially sensitive and may experience stress when exposed to situations such as competition, training, travel, lay-up due to sickness or injury, shows or events, limited turnout or grazing, or trailering.