- Induction of acute acalculous cholecystitis was studied in dogs. Designed models included ligation of the cystic artery and/or duct separately or combined and injection of colonic flora into the gallbladder. Cholecystectomy was performed 72 h later. Histological studies of the gallbladders and bile cultures demonstrated various degrees of cholecystitis, the severest form occurring as a result of cystic artery ligation, whereas the mildest was produced by injection of bacteria. Secondary infection was a constant feature of our experimental models.