Overview

• Cholic and chenodeoxycholic acids (primary bile acids) synthesized in liver from cholesterol   →   conjugated with taurine (preferred) or glycine and excreted in bile as their sodium salts (bile salts).
• Discharged at time of eating to small intestine where they assist in fat digestion.
• Only 2-5% of total bile acids are lost in faces each day - remainder resorbed, pass to the liver where extracted and re-excreted (enteropathic circulation).
• Small proportion reach general circulation - it is these that are measured.
• Sensitive indicator of liver function and of integrity of liver, biliary and intestinal circulation.

Sampling

Tests

Methodologies

• Enzymatic: more common (and accurate).
• Radio-immunoassay (RIA) (uncommon in veterinary laboratories).

Availability

• Commercial laboratory.

Technique (intrinsic) limitations

• Measurements of total serum bile acids (TSBA) not indicated when jaundice is present because hyperbilirubinemia is present and increased affecting TSBA.
• TSBA may be warranted in icteric animal if hemolysis cannot be ruled out. If hemolytic disease is the cause of jaundice TSBA are expected to be within normal limits.
• RIA method less accurate.
• Interpret results in conjunction with other laboratory results (liver enzymes) and/or liver biopsy.

Technician (extrinsic) limitations

• Depends on methodology.

Result Data

Further Reading

Publications

Refereed papers

• Recent references from VetMedResource and PubMed.
• Center S A, Erb H N & Joseph S A (1995) Measurement of Serum Bile and Concentrations for Diagnosis of Hepatobiliary Disease in Cats. JAVMA 207, 1048-1054.
• Sutherland R J (1989) Biochemical evaluation of the hepatobiliary system in Dogs and Cats. Vet Clin North Am Small Anim Pract 19 (5), 899-927.
• Center S A, Bladwin B H, Erb H & Tennant B C (1986) Bile acid concentrations in the diagnosis of hepatobiliary disease in the cat. JAVMA 189 (8), 891-896.
• Center S A, Bladwin B H, King J M & Tennant B C (1983) Hematologic and biochemical abnormalities associated with induced extrahepatic bile duct obstruction in the cat. Am J Vet Res 44 (10), 1822-1829.

Other sources of information

• Ettinger S J & Feldman E C (2000) Eds. Textbook of Veterinary Internal Medicine. 5th edn. W B Saunders & Co, USA.
• Kaneko J J, Harvey J W & Brass M L (1997) Eds. Clinical Biochemistry of Domestic Animals. 5th edn. Academic Press, USA.
• Duncan J R, Prasse K W & Mahaffey E A (1994) Veterinary Laboratory Medicine. Clinical Pathology. 3rd edn. Iowa University Press, USA.