Yellow Discoloration (Jaundice/Icterus): Cat Kidney Disease Glossary

Yellow Discoloration (Jaundice/Icterus) also known as Icterus, is defined as the yellowing of the skin, mucous membranes, and whites of the eyes (sclera). It is caused by the accumulation of bilirubin, a yellow pigment formed from the breakdown of red blood cells.

In the Chronic Kidney Disease (CKD) cat, Jaundice is a catastrophic complication. It usually signals that a second organ system, the liver, is failing alongside the kidneys.

The "Starvation" Spiral (Hepatic Lipidosis) The most common cause of jaundice in CKD cats is Hepatic Lipidosis (Fatty Liver Disease).

The Trigger: A CKD cat feels nauseous and stops eating (Anorexia) for as little as 2 to 3 days.
The Mechanism: The body panics and mobilizes fat reserves to the liver to be converted into energy. However, the feline liver cannot process this much fat at once.
The Clog: The liver cells become swollen with fat and stop working. Bilirubin backs up into the blood, turning the cat yellow.

The "Yellow" Signs The yellow color is often subtle at first.

The Ears: Look at the inside of the ear flap (pinna). In a healthy cat, it is pink or pale. In a jaundiced cat, it has a distinct yellow or orange tint.
The Eyes: The white part of the eye (sclera) turns yellow.
The Urine: The urine becomes a dark, neon orange or brown color ("Coca Cola urine") because the kidneys are filtering out the excess bilirubin.

The "Anemia" Link (Hemolysis) Rarely, jaundice can be "Pre-hepatic."

The Mechanism: If the red blood cells are being destroyed too rapidly (Hemolysis), perhaps due to a reaction to medication or oxidative damage (Heinz Body Anemia), the liver is overwhelmed by the waste products.

Disclaimer: This content is for educational purposes only and does not constitute veterinary medical advice. Always consult with your primary care veterinarian or a veterinary internal medicine specialist regarding your cat’s specific condition.

In the Chronic Kidney Disease (CKD) cat, Jaundice is a catastrophic complication. It usually signals that a second organ system, the liver, is failing alongside the kidneys.

The "Starvation" Spiral (Hepatic Lipidosis) The most common cause of jaundice in CKD cats is Hepatic Lipidosis (Fatty Liver Disease).

The Trigger: A CKD cat feels nauseous and stops eating (Anorexia) for as little as 2 to 3 days.
The Mechanism: The body panics and mobilizes fat reserves to the liver to be converted into energy. However, the feline liver cannot process this much fat at once.
The Clog: The liver cells become swollen with fat and stop working. Bilirubin backs up into the blood, turning the cat yellow.

The "Yellow" Signs The yellow color is often subtle at first.

The Ears: Look at the inside of the ear flap (pinna). In a healthy cat, it is pink or pale. In a jaundiced cat, it has a distinct yellow or orange tint.
The Eyes: The white part of the eye (sclera) turns yellow.
The Urine: The urine becomes a dark, neon orange or brown color ("Coca Cola urine") because the kidneys are filtering out the excess bilirubin.

The "Anemia" Link (Hemolysis) Rarely, jaundice can be "Pre-hepatic."

The Mechanism: If the red blood cells are being destroyed too rapidly (Hemolysis), perhaps due to a reaction to medication or oxidative damage (Heinz Body Anemia), the liver is overwhelmed by the waste products.