The low-pressure duct perfusion model reliably produces acute pancreatitis in cats. The main pancreatic duct is made permeable in one of several ways: the perfusion of glycodeoxycholic acid along the main pancreatic duct, the administration of intragastric ethanol, the stimulation of pancreatic secretion into an obstructed duct, or the creation of acute hypercalcemia. Active pancreatic enzymes are then perfused through the main pancreatic duct via a catheter inserted into the duct in the tail of the gland, and acute edematous pancreatitis results. Simultaneous infusion of 16,16-dimethylprostaglandin E2 converts acute edematous into acute hemorrhagic pancreatitis. Histologically, the characteristic changes of human acute pancreatitis are manifest 24 h later: necrosis, polymorphonuclear leukocyte infiltrate, hemorrhage and edema.