A 4-month-old female Dachshund presented as a referral for vomiting. She had been evaluated by her family veterinarian three times within a month for episodes of vomiting that also included diarrhea. Medical management was prescribed following normal abdominal radiographs and a fecal exam. However, she continued to expel food soon after eating which prompted a referral to DoveLewis. Here, she had a normal physical exam and bloodwork. An abdominal ultrasound as well as thoracic radiographs were scheduled due to the concern for regurgitating instead of vomiting. Thoracic radiographs showed a moderately focally distended esophagus cranial to the cardiac silhouette (Figure 1). Top differentials for these image findings were a vascular ring anomaly or an esophageal foreign body.
Her case highlights the importance to distinguish the difference between vomiting and regurgitation as it changes the approach for diagnostics and treatment. Regurgitation is a passive expulsion of food and typically results from esophageal disease but can also include pharyngeal disease, gastric disease or neuromuscular disorders. Vomiting is active expulsion of food and is typically preceded by nausea and retching. Upon further questioning to the owners, this patient was regurgitating.
Based on her age, history, physical exam and diagnostics, a vascular ring anomaly was highly suspected. A surgical consultation with a thoracic CT scan was performed to confirm the diagnosis. Once a persistent right aortic arch with a left ligamentum arteriosum was confirmed, surgical intervention immediately followed to transect the periesophageal bands (the ligamentum) through a thoracotomy. She recovered uneventfully from surgery and elevated feedings were continued temporarily followed by transition to normal kibble.
Vascular rings are developmental anomalies of the great vessels that result in encircling of the esophagus and trachea by complete or incomplete ring. There are several types, but the most common is a persistent right aortic arch with a left ligamentum arteriosum. German shepherds and Irish setters appear to be overrepresented. Animals are usually normal until weaning with regurgitation starting after they begin to ingest solid food. Clinical signs are postprandial regurgitation of undigested food, slow growth, malnourished despite good appetite, and respiratory signs possible with aspiration pneumonia. The diagnosis is made from signalment, history, physical exam and results of radiology/CT scan or esophagoscopy. Thoracic radiographs show a dilated esophagus cranial to the heart with fluid, air or ingesta. The esophagus caudal to the heart is usually normal. On the VD projection, there is a characteristic marked, focal leftward curvature of the trachea with focal narrowing (Figure 2). Long term medical management is usually unrewarding because the degree of esophageal dilatation increases with age. Surgery is generally recommended to be performed as soon as possible after diagnosis. Although some dogs required dietary modification long term, the outcome can be good to excellent in the majority of cases.