Although ascites is widely reported in dogs, those of cirrhotic ascites are scanty, especially in Abuja, Nigeria, hence the need for this report on cirrhotic ascites in a 2-year-old Caucasian dog. The reported complaints of anorexia, weakness, and distended abdomen before the presentation for proper veterinary attention led to a tentative diagnosis of suspected liver-induced ascites. The dog later died while receiving treatment necessitating the performance of a post-mortem examination on the severely emaciated carcass, which had pale mucous membranes, distended abdomen, and slightly oedematous distal limbs. Grossly, the lungs had multiple areas of congestion with visible hydrothorax and hydroperitoneum while the liver was shrunken, firm, nodular, misshapen, and haemorrhagic. Pulmonary congestion and oedema characterized the lung microscopically. The liver showed hepatic haemorrhage, cytoplasmic vacuolation, and necrosis with mononuclear cellular infiltration, fibrous connective tissue proliferation, and nests of apparently normal hepatocytes. The positive alpha-smooth muscle actin and vimentin immunoreactivity confirmed the hepatic fibrosis. Microscopic renal lesions indicated nephropathy. Consequently, the definitive diagnosis became cirrhotic ascites. The observed liver pathology indicated end-stage liver damage responsible for the ascites and eventual death of the dog. Prompt diagnosis with appropriate treatment is very crucial in the prognosis of cirrhotic ascites in affected dogs.