Megaesófago por persistencia del cuarto arco aórtico derecho en un perro pastor alemán

a secondary megaesophagus, as a result of vascular ring anomalies, was diagnosed in a nine-week old female german shepherd dog, with a history of intermittent regurgitation soon after weaning, respiratory disturbances, weight loss and growth retardation. a survey thoracic radiographs and a barium esophagogram confirmed the presence of a large esophageal dilatation cranial to the base of the heart, formed by three sacculations. a month later, the patient underwent a left intercostal thoracotomy to transect the ligamentum arteriosum to release the esophageal constriction. this procedure allowed to establish the definitive diagnosis of acquired secondary megaesophagus due to persistence of the fourth right aortic arch. after surgery, a feeding method was restarted in an upright position, with a soft diet, which was maintained with slight variations on a permanent basis. the patient showed a complete remission of clinical signs, despite the persistence of the megaesophagus, reaffirming that both the surgical correction of the vascular ring and an appropriate feeding method, help in controlling the disease in the long term. a report of the clinical evolution of the patient over 11 years and the results of radiographic studies conducted throughout this period are shown.