Case Report: An anomalous drainage of the left hepatic vein, a persistent left cranial vena cava, and an abdominal arteriovenous fistula in a Devon Rex cat.

A 6-month-old intact male Devon Rex cat was presented for a routine health evaluation prior to castration, with no apparent clinical signs. Following the incidental discovery of a caudal thoracic mass suggestive of a diaphragmatic abnormality on pre-anesthetic radiographs, computed tomography angiography was performed for further evaluation. The imaging revealed multiple congenital vascular anomalies, including an anomalous left hepatic vein draining directly into the right atrium, a persistent left cranial vena cava, an abdominal arteriovenous fistula, and a left phrenicoabdominal vein variant associated with a suspected peritoneopericardial diaphragmatic hernia. To the authors' knowledge, this is the first veterinary report describing direct drainage of the left hepatic vein into the right atrium in a cat. Awareness of such anomalies is crucial in preventing potential complications during surgical or interventional procedures.