Fluoroscopic and endoscopic diagnosis of a lower esophageal ring causing foreign body impaction in a dog.

A dog was presented because of regurgitation over a 3-day period. Radiographic examination revealed a bean-shaped filling defect and an annular narrowing at the level of the gastroesophageal sphincter. The contractile ring-like structure was sharply demarcated, and its appearance varied according to gastroesophageal distension. Endoscopic findings revealed lower esophageal ring and foreign body impaction.