Idiopathic gastroesophageal reflux disease in an adult horse

Chronic gastroesophageal reflux disease was diagnosed in a 22-year-old female Tennessee Walking Horse that had signs of bruxism and ptyalism. Esophageal ulceration was detected via endoscopy. Compared with the damage to the proximal portions of the esophagus, the severity of the ulceration increased toward the gastroesophageal junction. Esophageal ulceration attributable to chronic gastric acid reflux is usually secondary to pyloric outflow obstruction in horses. In the horse of this report, there was no evidence of either a chronic pyloric or duodenal obstruction that could have resulted in esophageal ulceration. Esophageal ulceration in this horse was attributed to gastroesophageal reflux disease, a common condition in humans in which the underlying abnormality is functional incompetence of the gastroesophageal junction. Treatment is directed at decreasing gastric acidity and protecting the ulcerated mucosa. In the horse of this report, treatment was unsuccessful and the horse was euthanatized; a physical cause of gastroesophageal reflux disease was not identified during an extensive postmortem examination.