Gastric ulcers have been described in people, swine, cattle, small animals, and horses, and they were first recognized in horses in the 1960’s. The clinical signs associated with this disease include depression, abdominal pain, teeth grinding, drooling, and a tendency to lie for long periods of time. In adult horses, gastric ulcers usually present as chronic recurrent colic, acute colic, poor body condition, loss of appetite, and/or soft feces. In foals, however, the signs can be much more severe.
The factors predisposing horses to the build-up of
stomach acid that causes ulcers are stress, long periods of time
without food, and the extended use or use of large amounts of
non-steroidal anti-inflammatory drugs such as phenylbutazone (bute)
or flunixin meglumine (banamine) to control pain. The use of these
anti-inflammatory drugs can cause ulceration not only in the
esophagus and stomach, but also in the colon.
Who is at risk?
• All horses that are under pressure due to competitions, dressage,
and racing are at a risk.
• Horses that are fed on a twice daily schedule with long periods
time with no access to food.
Gastric ulcers are suspected in horses with clinical signs such as
depression, weight loss, poor performance and mild colic after
eating. The degree and severity of ulceration are determined by
visualizing the stomach via gastroscopy.

A B C
Panel A represents a foal with gastric ulcers
showing the clinical signs of drooling (arrow) and teeth grinding.
Panel B and C represent a gastroscopy photograph of bleeding gastric
ulcers in a horse.
Although the treatment may vary depending on the severity of the
ulcers and their location, therapy is aimed at controlling the pain
and lowering the levels of gastric acid. This is typically achieved
by putting horses on oral medication to coat the ulcers (mucosal
protectants) and medication to heal the ulcers. Depending on
response to treatment, 14-28 days of medication are typically
required for healing. Most ulcers will be gone at 28 days, but some
may require longer therapy.
It may seem tempting to treat your horses at home with Pepcid®,
Tums®, Pepto-Bismol®, Maalox® or other similar antacids sold for
humans. The amount necessary to treat a horse with any of these
substances would be monumental and would not control the pain nor
heal the ulcers. Additionally, having to give repeated doses of
these types of medication require a lot of time and restraint and
may sour your relationship with your horse and cause him or her to
resist treatment.
How can I avoid ulcers?
Feed your horse smaller meals throughout the day
Increase the levels of good quality roughage, free choice good quality grass hay is ideal.
Allow your horse to graze
Before treating your horse with banamine or bute for colic or
lameness, discuss dosing amounts and frequencies with your
veterinarian. If these drugs need to be given over a long period of
time, supplementing the feed with half a cup to one cup of vegetable
oil may protect the colon from ulcers.