Young dogs may have a disorder of esophageal dysmotility without overt megaesophagus. Clinical signs can be similar to those of megaesophagus, although some dogs without clinical signs have abnormal motility during an esophagram. In one study in more than half the cases, the condition improved or resolved with age. Terrier breeds were overrepresented. Cats can also have esophageal dysfunction, which can be idiopathic; congenital; or secondary to myasthenia gravis, mediastinal masses, vascular ring anomalies, dysautonomia, and strictures. Many cats improve with medical management such as the use of sucralfate, H2-blockers, and metoclopramide.