This discussion was extracted from the broader article discussing colic (also on this web site) by Dr. Terry Gerros.  We chose to highlight this topic because it has particular value and application to miniature horses in general and foals in particular.  In addition to what Dr. Gerros describes in detail here, we have read numerous other publications that state ulcers are more prevalent in horses than most people recognize and can be a real source of problems.  Horses are prone to stress whether it be from travel, illness, medication, the show and training environment, moving to new surroundings, changes in feed and the list goes on.  Horse owners need to be aware of the tendency toward ulcers and the debilitating effect they can have.  The article that follows is very detailed as well as being technical but provides a great source of information on this important subject. Although this article discusses primarily foals, it applies equally to all horses particularly those in stressful situations.

Terry C. Gerros, DVM, MS, Diplomate, ACVIM

 

INTRODUCTION

Ulcers are defects in the gastrointestinal mucosa that penetrate the muscularis mucosa. This distinguishes them from superficial erosions that do not extend through the muscularis mucosa. In humans, the term peptic ulcer indicates ulcers which occur in the stomach, pylorus, or duodenal bulb but also can develop in the esophagus and the postbulbar duodenum.

 

There have been various hypotheses offered to explain the cause of gastroduodenal ulceration in foals, few have been proven. In general, ulcers occur when luminal aggressive factors overcome opposing mucosal defenses. There are four clinical syndromes of gastroduodenal ulcers which have been recognized: asymptomatic erosions and ulcers, symptomatic ulcers, perforating ulcers, and ulcer-associated gastric or duodenal obstructions.

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Diagnosis is based on clinical findings, contrast radiography, fiber-optic gastroscopy, and most recently determination of serum pepsinogen levels. Treatment has traditionally been with antisecretory drugs, cytoprotective agents, and antacids.

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GASTRIC PHYSIOLOGY

In addition to the mucus-secreting cells that line the surface of the stomach, the stomach mucosa has two different types of tubular glands: the oxyntic or gastric glands and the pyloric glands. The gastric glands contain chief (peptic) cells, parietal (oxyntic) cells, and mucous neck cells, which secrete pepsinogen, hydrochloric acid, and mucus, respectively. The pyloric glands primarily release mucus, for protection of the pyloric mucosa, pepsinogen, and the hormone gastrin (produced from gastrin (G) cells).