Gastric ulcers can affect a horse of any age and discipline.  The majority of horses with gastric ulcers are under heavy stress, such as performance or race horses.  However, retired pasture horses, non-performance horses, and even foals are susceptible to gastric ulcers.


What are gastric ulcers?

Gastric ulcers are erosions in the lining of the stomach due to prolonged exposure to the acid that is normally present in the stomach.


Why do horses get gastric ulcers?

Horses are designed to graze regularly, and therefore their stomachs continually secrete acid.  Regular intake of roughage neutralizes the acid in the stomach.  Often times gastric ulcers result from a horse not being able to eat regularly enough to neutralize the acid.  This often occurs with stall confinement and feedings twice per day, which results in a prolonged period without food intake.  Stressful environments can also contribute to the development of gastric ulcers, as well as a diet rich in grains but low in roughage.  Misuse of common anti-inflammatory drugs, such as chronic administration of phenylbutazone, can decrease the amount of mucus in the stomach lining and leave a horse more susceptible to gastric ulcers.


What is considered a “stressful environment”?

Many scenarios that a horse is exposed to daily can easily be categorized as stressful.  Training, hauling, weaning, and herd alterations are all commonly known to be stressful to a horse.  However, this often does not account for a horse with a retired, pasture lifestyle.  Unfortunately, our horses cannot tell us what is causing them stress.  Did your neighbor recently start renovating his house?  Did a tractor that has been parked in the same spot for 10 years recently get hauled away?  Any number of things can seem strange or new to a horse, and thus cause him or her stress.


What signs should I watch for?

Symptoms of gastric ulcers can often be subtle and hard to pinpoint.  Many times the horse will have a poor appetite for grains, or overall poor performance.  In more severe cases, the horse may have chronic bouts of mild colic.


How are gastric ulcers diagnosed?

The only definitive way of diagnosing gastric ulcers is through gastroscopy.  The horse is fasted for 12 to 24 hours, and withheld from water for 3 to 4 hours prior to examination, to ensure the stomach is empty.  The veterinarian uses an endoscope with a lighted camera on the end to pass through the nasal cavity and into the stomach to visually examine the stomach lining.  The procedure is non-invasive and performed similarly to passing a nasogastric tube for treating a colic.


How are gastric ulcers treated?

The only proven treatment gastric ulcers is GastroGard (omeprazole), which decreases the amount of acid produced by the stomach.  Sucralfate and ranitidine may also be prescribed to aid in acid reduction.

Altering the horse’s environment to reduce the level of stress is key to preventing continued issues with gastric ulcers.  Adding alfalfa to the horse’s diet is recommended for it’s neutralizing effects.  It is also recommended that the horse have access to free choice forage or more frequent feedings to reduce the amount of time without food.  For added protection, our veterinarians recommend the Platinum Performance Gastric Support supplement to maintain healthy levels of stomach acid.


Download our Equine Gastric Ulcer Syndrome (EGUS) Management Guidelines for a quick guide to gastric ulcers.


Adapted from “Equine Gastric Ulcers: Special Care and Nutrition” By Scott R. McClure, DVM, PhD, Diplomate ACVS, Diplomate ACVSMR