Acquired achalasia (megaesophagus) in a dog: clinical features and response to therapy.

Acquired megaesophagus was diagnosed in a mature mixed-breed dog. The onset of clinical signs, pattern of esophageal motility, and response to surgery differed from these factors in dogs with congenital megaesophagus. The dog improved following esophagomyotomy and feeding from an elevated container. Emptying of the esophagus improved postsurgically.