Is Your Cat Turning Yellow a Sign of Illness?

1 Understanding Cat Jaundice

I. What is cat jaundice

Jaundice is closely tied to excess bile pigment in the cat’s body. Normally the liver absorbs and excretes large amounts of bilirubin; if tissue or serum shows jaundice, it means bile pigment has built up persistently and the liver can no longer handle it—a liver problem.

Bilirubin is a product of heme-protein breakdown in animals and lives in the serum. If a cat’s serum bilirubin exceeds 5–10 times the normal level, jaundice likely appears—yellow gums, sclera, even whole-body skin. Human jaundice may be minor and fades, but in cats it is usually disease-driven.

II. When does a cat get jaundice

By cause, cat jaundice has three types: prehepatic, hepatic, and posthepatic.

1. Prehepatic: from increased red-cell breakdown raising blood bile-pigment levels. Causes include immune-mediated hemolysis, Heinz-body hemolysis, vitamin D deficiency, diabetes, and genetic disease.

2. Hepatic: linked to faulty uptake, binding, and excretion of bilirubin by liver cells. Causes include FIP, certain bacterial or fungal infections, liver parasites, poisoning, and liver tumors.

3. Posthepatic: mainly from abnormal bilirubin and bile excretion—bile-duct blockage, gallstones, cholangitis, and the like.

III. What to do about jaundice

Owners should know: signs like jaundice, vomiting, and diarrhea at most hint that one or a few adjacent organs are troubled, but can’t pinpoint the exact cause or whether it’s single. Treatment needs a confirmed diagnosis—which is why a vet matters; never medicate the cat yourself.

On seeing jaundice, do a self-check and suspect serious liver trouble, but it isn’t the only cause, so take the cat to a clinic first.

Generally prehepatic and hepatic jaundice respond to medication (e.g., a bile-acid liver supplement) plus nutritional support; posthepatic jaundice needs surgery to clear the bile duct, as drugs alone won’t suffice.