Gastric Ulcers in Horses

January 5, 2009 (published) | August 28, 2017 (revised)

Stomach ulcers are a common problem in performance horses. It is important to know that the horse's stomach has two distinct areas, a squamous or non-glandular portion and a glandular portion. It is the non-glandular portion that most commonly has ulcers in performance horses. The reason this part becomes ulcerated is because there is no protection from stomach acid and exercise allows stomach acid to be splashed up onto the unprotected area and allows ulcers to develop. This is one of the reasons almost 100 percent of thoroughbred racehorses have some degree of ulcers after being in training for only 2 to 3 months. And 60 to 90 percent of standardbred racehorses, show horses, pleasure horses and endurance horses in training also have ulcers, so any horse that is in training is susceptible to some degree of ulceration.

Stress also plays a role in the ulcers of the squamous portion of the stomach as ulcers have been shown to increase with certain trainers, urban location of stables, and a lack of contact with other horses. Ulcers in the glandular portion of the stomach is a completely different syndrome from ulcers in the non-glandular or squamous portion and the reason this is important is that lots of horses are treated with drugs like bute and Banamine, and folks are always concerned about using these drugs because they could cause ulcers. They can cause ulcers at higher than normal doses, but the ulceration is in a totally different area from ulcers caused by stress and training. So if your horse is prone to ulcers of the stomach's non-glandular portion due to training, it does not necessarily mean they are more likely to develop ulcers with bute or Banamine.

VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email

Information and opinions expressed in letters to the editor are those of the author and are independent of the VIN News Service. Letters may be edited for style. We do not verify their content for accuracy.