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
result from increased intraluminal pressure or deep esophageal inflammation, which can lead to mucosal herniation
predisposing conditions: esophagitis Esophagitis in Small Animals Inflammation of the esophagus is usually due to foreign bodies, gastroesophageal reflux, and occasionally certain drugs (eg, doxycycline). Gastroesophageal reflux is usually associated with... read more , esophageal stricture Esophageal Strictures in Small Animals Esophageal stricture is a pathologic narrowing of the lumen that may develop after anesthesia, trauma (eg, foreign body), ingestion of caustic substances, exposure to certain drugs (such as... read more
, foreign bodies Esophageal Foreign Bodies in Small Animals Esophageal foreign bodies are more common in dogs than in cats. Bones are the most common foreign body; however, needles, fishhooks, wood, rawhide, and dental chew treats may also become lodged... read more 
, vascular ring anomalies Vascular Ring Anomalies in Animals Pairs of embryonic aortic arches exist during early fetal development and subsequently give rise to the carotid arteries (third arches), the aortic arch (left fourth arch), and the pulmonary... read more , megaesophagus Dilatation of the Esophagus in Small Animals Megaesophagus may be due to a congenital defect or may be an adult-onset, acquired disorder. Congenital defects that may result in megaesophagus include: vascular ring anomalies esophageal diverticula... read more 
, and hiatal herniainvolve esophageal mucosa, submucosa and muscularis
Traction diverticula
result from inflammation in the chest cavity in close proximity to the esophagus
fibrous tissue is produced, then contracts, pulling esophageal wall outward
involve 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; however, 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.
