Felis ISSN 2398-2950

Blood biochemistry: bile acid

Synonym(s): Bile salts

Contributor(s): Kathleen P Freeman


  • 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.


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


  • 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

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Further Reading


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