International audience | OBJECTIVE To report clinical signs, biological anomalies, treatment, and outcome in domestic ferrets with cholecystitis, describe the ultrasonographic features of cholecystitis, and compare the ultrasonographic appearance of the hepatobiliary system between diseased and healthy ferrets. METHODS 11 ferrets with confirmed cholecystitis and abdominal ultrasonography were retrospectively included. Ten healthy ferrets were prospectively recruited to undergo hepatobiliary abdominal ultrasonography. Comparisons of explanatory variables (group, age, body weight, and sex) were performed. RESULTS The most common clinical signs were nonspecific, and icterus was observed in 1/4 of diseased ferrets. Compared with healthy individuals, diseased ferrets showed a larger common bile duct (CBD; ≥ 2.8 mm), a thicker CBD wall (≥ 0.7 mm), a thicker gallbladder (GB) wall, more frequent echoic GB luminal content, visible intrahepatic bile ducts, and a greater GB volume. Bile culture was positive in 9/11 mostly for Escherichia coli (8/9). Bile cytology indicated septic purulent cholecystitis in 7/7 ferrets. Survival time after antibiotic treatment ranged from 6 to 104 weeks, with a median of 36 weeks. CONCLUSIONS Ferrets with cholecystitis presented with nonspecific clinical signs and frequently showed hyperbilirubinemia. Ultrasonography findings such as enlarged CBD, thickened CBD wall, thicker GB wall, GB sludge, visible intrahepatic bile ducts, and enlarged GB may suggest cholecystitis. Escherichia coli was commonly isolated from bile. The medium-term mortality rate was high despite targeted antibiotherapy. CLINICAL RELEVANCE This is the first study describing the clinical signs, biological anomalies, ultrasonographic findings, and outcomes after treatment in a series of domestic ferrets with cholecystitis.