How to Feed Horses With Gastric Ulcers

Equine gastric ulcer syndrome (EGUS) affects more than 80% of Thoroughbred racehorses and 30-50% of all foals and weanlings. Incidence is similarly high in performance horses.

Because diet plays such an important role in managing ulcers, Ingrid Vervuert, DVM, described feeding strategies for affected horses at the 2016 American Association of Equine Practitioners Convention, held Dec. 3-7 in Orlando, Florida. Vervuert is an Assistant Professor at the Institute of Animal Nutrition, Nutrition Diseases and Dietetics and the Faculty of Veterinary Medicine at the University of Leipzig, in Germany, where she focuses her research on equine nutrition and dietetics.

Risk Factors

Based on previous research, we know that horses without access to any type of feed for more than eight hours are at risk for developing ulcers. Other significant risk factors include forage intake of less than 1% of body weight, high starch intake, limited pasture access, stall confinement, non-steroidal anti-inflammatory drug administration, strenuous exercise, and transport stress, said Vervuert.

Feed an Ulcer?

Horses evolved eating small meals throughout the day, so allowing a horse access to hay or forage on a continual basis ensures the stomach is not empty for long periods. A horse’s minimum daily forage intake should be >1.5 % of body weight (based on dry matter intake).

Some horses, especially high-performance animals, need supplemental grain concentrates to maintain condition. In these cases, divide grain meals into several small portions given throughout the day to balance nutrient intake, especially if feeding high-starch grain. To be sure performance horses are consuming sufficient energy without taking in excessive amounts of starch, owners might replace part of their high-starch grain rations with high-fat vegetable oils.


To date, the only effective treatment for eliminating ulcers is the drug omeprazole. Manufacturers offer a plethora of supplements that claim to ease, help, or cure EGUS, but most claims have little scientific proof—with a few exceptions, said Vervuert.

Researchers have shown that buffering substances, including aluminum hydroxide and magnesium hydroxide, increase gastric pH 30 to 120 minutes after oral supplementation, but their effect is short-lived. (Increasing gastric pH weakens the strength of acid, lessening its eroding effects on the stomach lining.) Some study results have shown that these substances have little to no benefit in foals.

In another study, a pectin-lecithin complex produced mixed results, but study designs were inconsistent and the results are difficult to interpret as a whole, she said.

Fortunately, she added, there is one “supplement” that is readily available, important for the diet, and proven to help in EGUS cases—hay!

Take-Home Message

One of the best strategies for managing EGUS is to provide constant access to forage, with gaps no longer than four to five hours, said Vervuert. If available, allow your horse plenty of pasture access as a natural way to consume roughage. Limit concentrate intake, and use fat as an energy supplement for horses that need extra calories.