Extrahepatic biliary tract obstruction: a retrospective study of 45 cases (1983-1993).

The medical records of 41 dogs and four cats with either surgical or postmortem confirmation of extrahepatic biliary tract obstruction were reviewed. Clinical signs of icterus, vomiting, anorexia, or a combination of these signs were exhibited by 100% of cases. Elevated serum bilirubin was documented in 37 of 41 dogs and two of four cats (86.6%). The predominant, underlying, pathological process was extraluminal obstruction of the biliary tract due to pancreatitis (19 of 45 cases; 42.2%) or neoplasia (11 of 45 cases; 24.4%). Biliary tract surgery was performed in 29 cases, of which 12 (41.3%) recovered. Animals diagnosed with extrahepatic biliary tract obstruction had a relatively good long-term prognosis, provided they were not compromised substantially due to severe necrotizing pancreatitis or neoplasia.