Budd-Chiari-like syndrome (BCLS) is an unusual condition in dogs that is characterized by ascites, hepatomegaly, and abdominal pain due to post-hepatic portal hypertension. There is not general agreement in veterinary medicine regarding the precise application of the "Budd-Chiari" terminology, however, BCLS should be distinguished from Budd-Chiari syndrome (BCD) based upon the location of the lesion that causes portal hypertension. This case report examines the diagnosis and treatment of BCLS in an adult Labrador retriever that resulted from positionally dependent compression of the caudal vena cava by a thoracic mass.