A 5-years-old female pointer dog was submittedto the hospital with the disease history of gradual distension of abdomen and emaciation for two months. An applesized hard mass was palpated on the right costal arch on physical examination. On blood chemical analysis, the marked elevation of SALT and decrease in serum albumin were detected. On paracentesis, a large volume of blood tinged fluid was detected. The peritoneal fluid contained tumor cells and the numerous blood cells. At autopsy the tumor mass located in the left medial lobe of liver was whitish and firm, and was consisted of many cysts. Histologically the tumor was identified as typical cholangiocellular carcinoma. Metastatic lesions of the tumor were detected in the lung, stomach, spleen, diaphragm, and lymph glands. This observation indicates that the cytological examination of the abdominal fluid have a diagnostic significance in the clinical examination of patients with abdominal tumors.