Abstract: An 8-year-old Bichon Frise was presented with abnormal behaviors such as unresponsiveness and salivation. Laboratory tests showed that the dog’s blood ammonia concentration was increased and serum urea nitrogen concentration was decreased; combined with the dog’s medical history of kidney stones and bladder stones, the initial diagnosis was portosystemic shunt. Further examination by CT angiography confirmed that the dog had a portosystemic shunt, and the shunt vessel was located between the left gastric vein and the azygos vein, belonging to the port-azygos shunt. The dog underwent elective surgery, and a cellophane band was used for shunt vascular occlusion during the operation. The dog had a good prognosis. The results suggested that cellophane band worked well in the treatment of canine port-azygos shunt.