Extrahepatic Biliary Tract Obstruction

The diseases that lead to a need for surgery of the extrahepatic biliary tract (EHBT) in dogs are primarily acquired conditions and include EHBT obstruction, gallbladder mucocele, traumatic injury, and cholecystitis. The main goal of surgery is to confirm the underlying disease process, establish a patent biliary system, and minimize perioperative complications. Clinical signs in dogs with surgical diseases of the biliary tree are nonspecific and mimic other abdominal disorders. Radiography should be undertaken in veterinary patients with clinical signs and laboratory abnormalities consistent with biliary disease. Hepatobiliary scintigraphy in animals with hepatic and biliary disease has been investigated and used clinically in patients with EHBT obstruction and may be a valuable diagnostic tool for differentiating EHBT obstruction from hepatocellular disease. Causes of EHBT obstruction in small animals include cholelithiasis, neoplasia, pancreatitis, inspissated bile, gallbladder mucoceles, parasites, duodenal foreign body, and diaphragmatic hernia.