Page 429 - Problem-Based Feline Medicine

21. The yellow cat or cat with elevated

liver enzymes

Albert E Jergens

KEY SIGNS
● Jaundiced cat.

MECHANISM?
● Jaundice occurs when serum bilirubin values exceed 2.0 mg/dl.
Jaundice results from either increased erythrocyte hemolysis or hepatobiliary disease.

WHERE?
● Pre-hepatic (hemolytic processes), hepatic (parenchymal disease), or post-hepatic (extra-
hepatic biliary obstruction).

WHAT?
● Most cats with jaundice have hepatic lipidosis, cholangiohepatitis syndrome (CHS), or extrahepatic
biliary obstruction (EHBO).
Non-jaundiced cats with elevated liver enzymes may or may not have liver disease. The degree
of dysfunction is assessed by bile acid analysis and the cause determined by liver cytology
and/or biopsy if indicated.

QUICK REFERENCE SUMMARY
Diseases causing a yellow cat or cat with elevated liver enzymes

PRE-HEPATIC
● Hemolytic processes causing clinical signs are usually associated with PCV < 18%.
INFLAMMATION
INFECTION

● Mycoplasma haemofelis *(Hemobartonella felis)* (p 424)
Bacterial (Mycoplasma) parasite which infects red blood cells and causes RBC destruction.
Jaundice, lethargy, inappetance and occasional vomiting.
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