Stomach ulcers are common in performance horses; 90 percent of race horses and a large percentage of other performance horses have been shown to have ulcers. There are two types of stomach ulcers in horses because there are two distinct areas of the horse’s stomach. One area is the glandular stomach, which is protected by mucous and other barriers. The most likely cause of ulcers in this area is stress or medications like butazolidine for pain and these ulcers are rare.

The most common type of ulcer is in the nonglandular part of the stomach and is generally not related to being given butazolidin but it is related to exercise, diet, and the stress of being kept in a stall and not being allowed to graze. This area of the stomach is not protected and since the horse’s stomach secretes acid continually, horses fed just twice a day in a stall have no protection so ulcers develop, especially when the horses are exercised. 

The only approved treatment of stomach ulcers is a drug called GastroGard that increases the pH of the stomach by decreasing gastric acid, and it is effective. However, it is expensive especially with long-term treatment and as soon as the drug is stopped, ulcers will recur. There are multiple products on the market that claim to decrease ulcers but there is no evidence to support their use in most cases. However, the vets at LSU performed a study using a commercially available supplement called Smart Gut Ultra Pellets and found that after stopping GastroGard, the Smart Gut product decreased ulcer formation compared to untreated horses.