SYMPTOM
Jaundice (yellowing of skin or eyes)
A yellowish discolouration of the whites of the eyes, the inner ear flaps, the gums, or the skin, most visible in lightly pigmented areas and indicating elevated bilirubin levels.
Hepatic (Liver) Disease
Jaundice most commonly reflects dysfunction of the liver's ability to process and excrete bilirubin, a breakdown product of haemoglobin from red blood cells. Hepatic lipidosis in cats, cholangitis/cholangiohepatitis, toxic hepatopathy, hepatic neoplasia, and cirrhosis can all produce jaundice by impairing the liver's bilirubin conjugation and excretion pathways. The degree of jaundice often correlates with the severity of hepatic compromise, though this relationship is not absolute.
Biliary Obstruction (Post-hepatic)
Obstruction of the bile ducts — from gallstones, biliary sludge, pancreatitis causing compression of the common bile duct, or biliary tumours — prevents conjugated bilirubin from reaching the intestine, causing it to accumulate in the blood. Post-hepatic jaundice may be accompanied by pale or acholic (clay-coloured) stools due to the absence of bile pigments in the intestine, and dark-coloured urine from renal excretion of conjugated bilirubin.
Haemolytic (Pre-hepatic)
Accelerated destruction of red blood cells releases bilirubin faster than the liver can process it, producing jaundice from bilirubin overload rather than liver dysfunction. Immune-mediated haemolytic anaemia, blood parasites (such as Mycoplasma haemofelis in cats), zinc toxicity, and certain infections can produce haemolytic jaundice. This form is often accompanied by anaemia, weakness, and sometimes dark-coloured urine from haemoglobin excretion.
Infectious
Certain infections have a predilection for affecting the liver or biliary system. Feline infectious peritonitis (FIP) commonly produces jaundice in cats through hepatic and peritoneal inflammation. Leptospirosis in dogs can cause both hepatic and renal damage with associated jaundice. Bacterial cholangitis and hepatic abscesses can produce jaundice through direct hepatocellular damage and biliary inflammation.
Toxic
Various toxins and medications can cause hepatocellular damage leading to jaundice. In cats, paracetamol (acetaminophen) toxicity produces both haemolysis and hepatic necrosis with rapid-onset jaundice. Certain plants, mushrooms, and chemicals can damage the liver sufficiently to impair bilirubin processing. Drug-induced hepatotoxicity from medications metabolised by the liver represents another potential cause.
Why timing matters
Early observation
Early jaundice may be subtle and easily missed, presenting as a faint yellowish tinge to the whites of the eyes (scleral icterus) or the inner surface of the ear pinnae. In animals with dark pigmentation, early jaundice may only be detectable on the gums, mucous membranes, or non-pigmented skin areas. The discolouration may initially be noticed only in bright natural light. At this early stage, the underlying bilirubin elevation may be modest and the animal may show few other signs, or may have non-specific signs such as mild appetite reduction or lethargy.
Later presentation
As bilirubin levels rise further, the jaundice becomes more obvious and widespread, with visible yellowing of the skin, mucous membranes, and even the fur in light-coloured animals. The urine may become noticeably darker as the kidneys excrete excess bilirubin. At this stage, the animal typically shows more pronounced signs of illness including significant appetite loss, lethargy, and possibly vomiting or diarrhoea depending on the underlying cause. Advanced jaundice may be accompanied by signs of hepatic encephalopathy if the liver's detoxification capacity is severely compromised.
The trajectory of jaundice depends on its cause. Haemolytic jaundice may develop rapidly over hours to days as red blood cell destruction accelerates. Hepatic jaundice from conditions like hepatic lipidosis may develop over days to weeks as liver function progressively declines. Obstructive jaundice may develop gradually or acutely depending on whether the biliary obstruction is partial or complete. Whether the jaundice is worsening, stable, or improving provides important information about the trajectory of the underlying disease process.
Conditions commonly associated
Hepatic Lipidosis in Cats
Hepatic lipidosis in cats often presents with jaundice as bilirubin accumulates due to impaired liver function from fat infiltration.
Immune-Mediated Haemolytic Anaemia (IMHA)
Jaundice develops in IMHA when the massive breakdown of red blood cells produces bilirubin faster than the liver can process and excrete it, leading to accumulation and visible yellowing of tissues.
Liver Disease in Dogs
Jaundice can be one of the more recognisable signs of significant liver disease, developing when the liver's ability to process bilirubin is compromised.
Feline Infectious Peritonitis (FIP)
Jaundice in FIP reflects hepatic involvement by granulomatous inflammatory lesions, leading to impaired bilirubin processing and the characteristic yellowing of mucous membranes, skin, and sclera.
Triaditis in Cats
Jaundice in triaditis reflects liver involvement, specifically cholangiohepatitis, which affects bile processing.
Gallbladder Mucocele
Obstruction of bile flow causes bilirubin accumulation and visible yellowing.
When to explore further
Any visible jaundice — yellowing of the eyes, gums, skin, or ear pinnae — represents a significant finding that warrants investigation, as it indicates bilirubin levels substantially above normal.
Jaundice developing in a cat that has had reduced appetite or has not been eating for several days, particularly if the cat is overweight, raises concern for hepatic lipidosis, a condition where early intervention significantly influences outcome.
Jaundice accompanied by anaemia — pale gums, weakness, rapid breathing — may suggest a haemolytic process where red blood cells are being destroyed faster than normal, producing bilirubin overload.
Jaundice developing alongside abdominal pain, vomiting, or fever may suggest an acute hepatic or biliary process such as cholangitis, pancreatitis, or biliary obstruction.
Rapidly worsening jaundice over hours to days, particularly if accompanied by deteriorating mental status or abnormal behaviour, may suggest acute hepatic failure or severe haemolysis that is progressing quickly.
Checking the colour of the whites of the eyes, the inner ear flaps, and the gums in natural daylight provides the most reliable visual assessment of jaundice. Noting the colour of the urine — whether it appears darker than usual — can provide additional information, as bilirubin excretion by the kidneys produces characteristically dark, amber-coloured urine. Observing the animal's appetite, energy level, and overall demeanour alongside the jaundice helps build a picture of the broader clinical status.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS