A Review of Disorders of the Gallbladder and Extrahepatic Biliary Tract in the Dog and Cat

Abstract

ALTHOUGH NOT AS commonly recognized as in human medicine, disease of the gallbladder and extrahepatic biliary tract does occur in dogs and cats. Lack of awareness of the signs of biliary tract disease is probably the reason these disorders are overlooked. These disorders are often confused with other intra-abdominal disorders because their course and clinical signs are similar. This review is twofold: to review the normal anatomy and physiology of the gallbladder, bile duct, and bile in the dog and cat; and to discuss the historic, physical examination, clinicopathologic, diagnostic, histologic, and therapeutic aspects of biliary tract disorders. AnatomyWithin the liver, bile drains through the canaliculi into interlobular ducts. These then unite to form the hepatic ducts that emerge from the lobes of the liver. The hepatic ducts are usually three to five in number, and empty into the cystic duct, which in turn drains into the gallbladder. After the last hepatic duct enters, the cystic duct becomes the bile duct (sometimes referred to as the common bile duct), and empties into the duodenum (1 5 6 . 0 cm) distal to the pylorus at the major duodenal papilla. ' The duct systems that deliver pancreatic and biliary secretions to the duodenum differ between the dog and cat. The distance between the entrance of the major pancreatic duct and the common bile duct into the duodenum is greater in the dog than in the The clinical importance of this difference is that a larger lesion in this

The Liver and Exocrine Pancreas

“…28 Fasting and 2-hour postprandial bile acid concentrations have the same normal range values irrespective of age and are increased with primary or cholestatic liver or gallbladder disease.…”

Liver and biliary tract

“…Other systemic effects of bile salts include red cell lysis, electrolyte imbalances, hypoproteinemia, anemia, and marked dehydration due to alkaline pH and hyperosmolality. 10 Bile peritonitis has been reported in a retrospective case series on 24 dogs and two cats, 100 as well as in a case report of one cat Section The Abdomen…”

“…The sympathetic innervation via the splanchnic nerves has the opposite effects. 10 Filling of the gallbladder occurs continuously and bile flow is driven by hepatic secretion and gallbladder contraction. This is a low-flow, low pressure system.…”

“…10,98 Two large retrospective case series have been published reporting on prognostic factors and outcome in biliary diversion surgeries in cats. 36,37 In one, the mortality rate within 48 hours of surgery was 57%; in cats diagnosed with neoplasia it was 100% versus those with non-neoplastic causes, where it was 40%.…”

Thoracic and Abdominal Trauma

“…52 It is reportedly more common for blunt trauma to result in ductal rupture than gallbladder rupture, usually just distal to the last hepatic duct. 52 It is reportedly more common for blunt trauma to result in ductal rupture than gallbladder rupture, usually just distal to the last hepatic duct.…”