Diverticula are pouch-like dilatations of the esophageal wall and may be congenital or acquired. They are rare in dogs and cats. Acquired diverticula are of two types: pulsion or traction. Pulsion diverticula are caused by increased intraluminal pressure or deep esophageal inflammation, which can lead to mucosal herniation. Predisposing conditions include esophagitis, esophageal stricture, foreign bodies, vascular ring anomalies, megaesophagus, and hiatal hernia. This type of diverticulum involves the esophageal epithelium and connective tissue. Traction diverticula result from inflammation in the chest cavity in close proximity to the esophagus. Fibrous tissue is produced, which then contracts, pulling the esophageal wall outward. This diverticulum involves all layers of the esophagus.
Small diverticula may be subclinical. Large diverticula allow food to become trapped in the pouch, leading to postprandial dyspnea, regurgitation, and anorexia. Survey radiographs may show the diverticulum if it is full of ingesta or air, but contrast radiographs are best to demonstrate the pouch. Endoscopy will also allow visualization and can identify ulceration and scarring.
Small diverticula may be treated with a bland, soft diet fed with the animal in an upright position. Large diverticula require surgical excision and reconstruction of the esophageal wall. The prognosis after surgery is fair to good.