Gastric ulceration
is a widespread clinical finding among performance horses in training
as well as in foals. Prevalence of up to 93% has been documented
among horses in race training,1 and in nearly 60% of other performance
horses.2
Ulcer
prevalence of up to 93% has been
documented among horses in race training
The disease
complex that precipitates ulceration of the esophageal, gastric,
or duodenal mucosa in the horse is referred to as Equine Gastric
Ulcer Syndrome (EGUS). It includes both asymptomatic and symptomatic
cases; focal or multifocal ulceration of squamous mucosa, glandular
mucosa, or both; and gastritis and complications of these disorders.3
EGUS
ranges from mild erosion
to craters that penetrate the mucosa
EGUS spans
a spectrum of severity, ranging from inflamed but intact epithelium
to single, superficial erosions of the mucosal surface, and from
there to multiple actively hemorrhaging hyperemic and/or necrotic
craters extending beneath the mucosal surface.4 Perforation may
occur, and when it does it is usually fatal.5
Endoscopy
provides a definitive diagnosis, but it requires endoscopes of
3 meters (9.8 feet), which may not be available in many localities.
However, a variety of clinical signs, such as reduced appetite,
poor body condition, poor performance, diarrhea, and colic, may
be highly suggestive of gastric ulceration. Response to empirical
antiulcer therapy may help establish the diagnosis in the absence
of endoscopy.
In
addition to intensive training, other risk factors that may predispose
horses to gastric ulceration include intermittent feeding, reduced
hay intake, physical stress (such as injury, illness, and hospitalization),
other stressors (such as shipping, relocation, and resocialization),
and, possibly, high doses of some medications. Helicobacter pylori
, a bacterium that is a major factor in the development of human
ulcers, has not been isolated from horse stomachs and is not currently
considered to be a cause of horse ulcers.3
Frontiers
in Treatment
EGUS
is increasingly recognized as a major problem affecting the well-being
and performance of horses. Antacids, histamine H2 antagonists,
ulcer-coating agents such as sucralfate, synthetic prostaglandins,
and anticholinergics have been used to treat gastric ulcers in
horses. None of these products is approved by the FDA for use
in horses, and their effectiveness and safety have not been assessed
in large-scale, placebo-controlled trials. Limited reports of
the use of these agents show variable results, and there is no
recommended dose or administration schedule. Importantly, horses
must be removed from training to achieve healing of stomach ulcers
if these agents are used.3 Omeprazole, an acid pump inhibitor,
is the most widely prescribed antisecretory ulcer medication in
humans and the number one. selling prescription drug in the world.
A potent suppressor of gastric acid secretion, omeprazole is inherently
long-acting and generally well-tolerated. These are desirable
characteristics in an equine medication, and formed the initial
basis of developing an omeprazole-based product for equine use.
Adapted
for Equine Use
GASTROGARDª
(omeprazole) Oral Paste for Equine Ulcers has been developed specifically
for horses. GASTROGARD is administered orally by syringe. A dose
of 4 mg omeprazole/kg/day has been shown to produce maximal suppression
of gastric acid secretion. Each syringe has sufficient omeprazole
paste to treat a 1250-lb horse.
