the possible relationship of megaesophagus and canine distemperin two german shepherd dogs

megaesophagus (esophageal dilatation) is a neuromuscular disease. in this disorder, the esophagus is abnormally stretched and air is collected with food in it. two male dogs aged 4 and 6-year-old, german shepherd breeds and weighing 18.4 and 23.2 kg were presented to the veterinary hospital of shahid chamran university with complaints of regurgitation, dehydration, anorexia, depression, dysphagia, myoclonus, hypersalivation, gurgling sound during swallowing and fatigue in the past month. they were not vaccinated against distemper and other viral diseases. physical examination revealed a relatively thin body condition. a plain radiograph of the chest revealedadvanced megaesophagus with aspiration pneumonia. rapid antigenic test (immunochromatography assay) was positive for canine distemper. cbc was abnormal (leucopenia, lymphopenia and neutropenia). supportive treatments were administered for them. we advised the dogs be placed in a vertical position for 15 min after the meal. only one dog was sent back home in good health four weeks later and the disease did not relapse for more than six months. the second dog had a symptom of megaesophagus and did not respond to supportive treatments completely. a possible relationship between megaesophagus and canine distemperinfection has been reported in the present survey.