Equine Gastric Ulcer Syndrome

region and contains glands that secrete among other things the hydrochloric acid and pepsin necessary for digestion. The nonglandular and glandular regions are divided by a stepped edge called the margo plicatus.
Gastric lesions including inflammation erosion and ulcers can occur in any region of the stomach although the clinical syndromes and pathophysiological mechanisms vary according to region. Accordingly the term Equine Gastric Ulcer Syndrome EGUS is used to describe a variety of different conditions including gastroduodenal ulcer disease most commonly seen in foals glandular gastric lesions related to the administration of nonsteroidal antiinflammatory drugs NSAIDs and trainingrelated nonglandular squamous disease.
Causes of Gastric Ulcers
Gastric ulcers form when there is an imbalance between the factors that incite erosion and the factors that protect the stomach. The most common inciting factor is hydrochloric acid although bile acids volatile fatty acids and pepsin may also contribute to disease development. Excessive acid exposure is the chief mechanism of nonglandular squamous disease. The specific protective mechanisms vary among regions of the stomach i e. the glandular and nonglandular regions.
Some external factors that can upset the balance between gastric erosion and protective mechanisms are
Diet Feeding Schedule A highconcentrate lowroughage diet and intermittent feeding are factors that increase the risk of a horse developing gastric erosion. Because the horse is a natural grazer designed to eat around the clock the horses stomach as part of the normal digestive process secretes hydrochloric acid regardless of whether the horse is actually eating. Feed material in the stomach acts as a buffer a substance capable of neutralizing the acid thereby maintaining normal acidity minimizing potential deleterious effects of the acid. If a horse is only fed twice a day there are prolonged periods when the stomach is empty thus leaving the stomach more susceptible to acid injury.
Exercise Intensity A study conducted by Orsini J. Hackett E. et al revealed that the prevalence and severity of trainingrelated nonglandular squamous disease increase with the duration and intensity of training. A second study LorenzoFigueras and Merritt in 2002 demonstrated that during exercise the horses stomach is compressed by the abdominal viscera and diaphragm forcing acidic contents proximally upward and inducing acidmediated injury to the nonglandular squamous mucosa. Horse owners riders and trainers need to be aware that increasing training intensity can predispose horses to gastric ulcer formation.
Illness The prevalence of gastric ulcers in critically ill foals is higher than in normal foals and it