Acute bacterial cholangiohepatitis of cats is a common disease associated with the inflammation of bile ducts and liver parenchyma, characterized by development of a pronounced hepatodepressive syndrome (hypoalbuminemia), cytolysis (increase in serum activity of alanine and asparagine transaminase), cholestasis (increase in serum concentration of bilirubin, cholesterol, activity of alkaline phosphatase and gamma-glutamyltranspeptidase), intoxication, dehydration, mesenchymal-inflammatory and pain syndromes. The aim of the research was to study the effectiveness of treatment for acute bacterial cholangiohepatitis in cats with average severity of the pathology course. According to inclusion and exclusion criteria, the study included a cohort of cats (n = 12) with acute bacterial cholangiohepatitis. Clinical, hematological, ultrasonographic, statistical methods of investigation were used in this work. For sick cats with medium severity form of cholangiohepatitis, when administered as a complex therapy the combination of marbofloxacin, metronidazole, ursodeoxycholic acid, cyancobolamine, tocopherol acetate, infusion therapy also had a good therapeutic effect, which was accompanied by improved clinical and laboratory performance. In the blood of cats with cholangiohepatitis, in the background of intensive therapy, there was a significant decrease in white blood cell count, erythrocyte sedimentation rate, and in serum, there was an increase in albumin concentration, reduction of creatinine, aminotransferase activity, alkaline phosphatase, gamma-glutamyltranspeptidase, lipase.