Necropsy examinations were performed on 100 dogs to study the biliary system, blood supply, and topographic anatomy of the liver. The major ligamentous attachments of the relatively mobile organ are the left triangular and hepatoduodenal ligaments. Considerable fixation is provided by the hepatic veins and the intimate attachment of the liver to the inferior vena cava.
The six lobes of the liver are arranged in three natural divisions. The portal vein, its branches, and their distribution are consistent as are major hepatic veins. The hepatic artery branches and major bile ducts have patterns which may be readily related to the divisional boundaries. The branches of the hepatic artery vary in number from one to five. Three branches were present in 64 of 100 specimens. A single gallbladder and cystic duct were found in each of 100 specimens. The common bile duct is formed from three (64%) or four (36%) major collecting or divisional ducts. When four divisional ducts are present, the right and left divisions of the liver are each drained by a single duct with two ducts draining the central division. The cystic duct may join either the right or left central divisional duct to form the common bile duct.