At the racetrack, Hay says, veterinarians give medications such as phenylbutazone, flunixin meglumine and nonsteroidal anti-inflammatory
drugs (NSAIDs) that tend to reduce horses' defense mechanisms to other diseases and conditions and, thus, predispose them
to ulcers. Meanwhile, the objective of pharmacologic treatment of ulcers in racehorses is to make them feel better, eliminate
clinical signs, promote healing and prevent recurrence so the horses eat well, maintain good weight and stay competitive.
To decrease gastric acidity, treatment options include H2-receptor antagonists and proton pump inhibitors. The H2-receptor antagonists block the interaction of histamine with H2 receptors on the parietal cell, decreasing hydrochloric acid secretion. They also partially inhibit feed- and pentagastrin-stimulated
Proton pump inhibitors block gastric acid secretion via irreversible inhibition of hydrogen-potassium ATPase, the final enzymatic
step in the acid secretory pathway.
Other possible drug therapies include synthetic prostaglandins, mucosal protectants and antacids, the latter of which neutralize
stomach acid usually via a mixture of aluminum and magnesium hydroxides. Young also recommends buffering agents, corrective
suspensions and various magnesium hydroxide products such as Pepto-Bismol or GastroCote (bismuth subsalicylate). "If given
daily, we see at least some cessation of signs. We don't think we're going to cure ulceration with those products, but at
least the horse will feel and eat better and, subsequently, will perform better," he notes.
All of that said, however, Young points to omeprazole as the "first line of defense" in his equine practice. "We feel that
GastroGard, a proton pump inhibitor, has the best results. Unfortunately, it is expensive. A lot of clients simply cannot
afford a daily tube of GastroGard, which can run veterinary bills up to $1,000 per month, just for trying to keep ulceration
He also uses compounded omeprazole, but cautions that he doesn't see the same level of results as with the GastroGard. "But
we do see some results and some cessation of signs," he says. "And from a financial perspective, our clients like compounded
omeprazole more on a daily basis."
If esophagogastroscopy finds significant ulcerations, Young strongly recommends that GastroGard be administered.
Controlling gastric ulcerations in racehorses is a complex process —one that requires reduced training, a change in feeding
regimen and perhaps pharmacologic administration.
Ed Kane, PhD, is a researcher and consultant in animal nutrition. He is also an author and editor on nutrition, physiology and veterinary
medicine with a background in horses, pets and livestock. Kane is based in Seattle.