Equine gastric ulcer syndrome
What is EGUS and what its cause? Equine Gastric Ulcer Syndrome is a complex multi-factorial disease that is not completely understood. There are many theories that have implicated stress, NSAID use (phenylbutazone & banamine), housing, exercise, and diet as risk factors. It is highly likely that all these factors contribute to development of EGUS.
Are there different types of ulcers? Equine gastric ulcers fall into one of two main categories; squamous or glandular. The horse stomach is divided into two compartments; the part closest to the opening of the esophagus is squamous section. This section is covered by squamous (skin like) cells that do not produce stomach acid. Nearly 80% of ulcers are found in this region. The other section is the glandular portion. This section contains the cells that secrete hydrochloric acid which is essential for digestion of food.
What are the clinical signs of gastric ulcers in adult horses? Clinical signs of ulcers can be somewhat vague in adults. These may include acute or recurrent colic (particularly after eating), loss of body condition, performance issues, changes in attitude, and frequent recumbency. With gastric ulcers a horse may be reluctant to eat grain or may take more time than usual to eat the grain. Gastric ulcers also occur secondarily to many conditions and horses are often placed on preventative (lower) or treatment (higher) doses during hospitalization.
How are gastric ulcers diagnosed? The most accurate method to diagnose gastric ulceration is by flexible endoscopy of the stomach. In this procedure, a 3 meter fiber optic scope is placed in the horse's nose and passed through the esophagus in order to visualize the stomach. Many horses tolerate this procedure very well and side effects are rare.
How should my horse be prepared for endoscopy? Your horse needs to have food withdrawn for a minimum of 12 hours and most clinicians prefer water taken away 3 to 4 hours prior to the procedure. This enables better visualization of the stomach. Some horses may require an additional fasting period.
What is the treatment for gastric ulcers? Depending on severity and clinician preference, horses are often placed on either omeprazole (Gastroguard) or ranitidine. These drugs work by inhibiting acid secretion in the stomach and consequently raising gastric pH. Unfortunately, due to breakdown of the active ingredient, the formulation of omeprazole is critically important and generic or compounded omeprazole is usually not effective. Treatment generally is for a month. Recheck endoscopy can help determine if further treatment is needed.