What causes ulcers in horses?
There are two forms of equine gastric ulcer syndrome: a) equine squamous gastric disease (ESGD); and b) equine glandular gastric disease (EGGD)—each syndrome occurs in a different part of the stomach. The greater the intensity of exercise, the greater the likelihood a horse will develop ESGD. In contrast, a horse ridden 6–7 days a week is 3.5 times more likely to have EGGD compared to five or fewer riding days a week. Other factors associated with EGGD include situations that add to behavioral stress, such as the number of riders and/or handlers a horse experiences, isolation of a horse from the herd, and social interaction.
Diagnosing equine gastric ulcer syndrome
In many cases, EGUS is accompanied by non-specific signs, such as poor performance; poor hair coat and/or body condition; poor appetite or finicky eating habits; unexplained weight loss; abdominal discomfort or colic; aggressive or nervous behavioral changes; and crib-biting or other stereotypic vices, like weaving, pawing, stall walking. Gastroscopy (passing an endoscope into the stomach) is necessary to confirm a diagnosis of EGUS.
How to treat ulcers in horses
Treatment of ESGD is based on acid suppression with medication, namely omeprazole (Gastroguard). The goal is to maintain the pH of the stomach above 4 for at least two-thirds of a 24-hour period, i.e. > 16 hours. This is best achieved by fasting the horse overnight, and then omeprazole is administered orally 60-90 minutes prior to the morning feed.
Preventing the formation of equine ulcers
Prevention of ESGD relies on dietary management along with lifestyle management that minimizes a horse’s stress – consider training, transport, and competition as well as stressful living and management situations on the farm. Dietary management is important for ESGD although it has little effect on EGGD. A horse that goes without feed for more than six hours is more at risk for the development of ESGD. Horses with at least some amount of turnout or free-choice hay are less likely to develop ESGD. Grain products (corn, oats, barley, sweet feed) should be fed in minimal amounts as their digestion results in volatile fatty acids that lessen stomach resistance to acid. Horses with limited or no access to water are more than 2-½ times as likely to develop EGUS so provide ample clean water. Rest days, at least two per week, are important to minimize the risk of EGGD.