Equine Gastric Ulceration Study Guide

Overview and Clinical Importance

Equine Gastric Ulcer Syndrome (EGUS) is an umbrella term describing erosive and ulcerative diseases of the equine stomach. EGUS is one of the most common gastrointestinal disorders in horses, with prevalence rates reaching 80-100% in Thoroughbred racehorses in active training. Understanding the distinction between Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD) is critical for the NAVLE, as these represent distinct disease entities with different pathophysiology, risk factors, and treatment responses.

The horse stomach is uniquely susceptible to ulceration due to continuous acid secretion regardless of feeding status, a relatively small stomach capacity (8-16 liters), and the presence of an unprotected squamous mucosal region in the proximal third of the stomach.

Gastric Anatomy and EGUS Terminology

Equine Stomach Anatomy

The equine stomach is a J-shaped, relatively small organ (capacity 8-16 liters) located primarily on the left side of the abdomen. It is divided into two distinct mucosal regions separated by the margo plicatus, a distinct ridge that marks the junction between the squamous and glandular mucosa.