Liver Disease in Cats: Signs, Causes & Treatment

By Sarah Bennett, Certified Animal Nutritionist

The liver is one of the most remarkable organs in a cat's body — it performs over 500 functions, from metabolizing nutrients and detoxifying the blood to producing bile for digestion and synthesizing essential proteins. When it fails, the consequences ripple through every body system. Liver disease in cats is more common than many owners realize, and it encompasses a wide range of conditions, some of which are life-threatening if not caught early. Understanding the warning signs, the most common diagnoses, and the treatment options available can genuinely save your cat's life.

The Most Common Forms of Feline Liver Disease

Hepatic Lipidosis (Fatty Liver Disease)

Hepatic lipidosis is the most common severe liver disease in cats and one of the most common causes of liver failure overall. It develops when a cat stops eating — for any reason — for even a few days. Unlike many other mammals, cats rapidly mobilize fat stores when caloric intake drops, but their livers cannot process this sudden influx of fat efficiently. Fat accumulates within liver cells, impairing function and eventually causing liver failure.

Obese cats are at highest risk, but any cat that stops eating due to stress, illness, or dietary change can develop hepatic lipidosis. The critical point: this condition is largely preventable and, if caught early, highly treatable. However, if left untreated it is fatal. Any cat that has not eaten for 48 hours or more needs veterinary evaluation.

Cholangitis and Cholangiohepatitis

Cholangitis refers to inflammation of the bile ducts, while cholangiohepatitis extends that inflammation into the surrounding liver tissue. There are two main forms: neutrophilic (bacterial, usually ascending from the intestines) and lymphocytic (immune-mediated). The neutrophilic form responds well to antibiotics; the lymphocytic form requires immunosuppressive therapy. These conditions are closely associated with inflammatory bowel disease (IBD) and pancreatitis — the so-called "triaditis" when all three occur together.

Portosystemic Shunts

Portosystemic shunts (PSS) are abnormal blood vessel connections that bypass the liver, meaning blood from the digestive tract reaches the systemic circulation without being detoxified. They can be congenital (present at birth, more common in certain breeds) or acquired (developing secondary to chronic liver disease). Young cats with PSS may show stunted growth, neurological signs-cat-loves-you" title="12 signs-cat-loves-you" title="12 Signs Your Cat Actually Loves You (Science-Backed)">Signs Your Cat Actually Loves You (Science-Backed)">signs after eating, or unusual behavior.

Hepatic Lymphoma and Other Tumors

The liver is a common site for lymphoma in cats, as well as metastatic spread of other cancers. Primary hepatocellular carcinoma is less common but does occur. Any mass discovered in the liver on imaging requires biopsy for a definitive diagnosis.

Signs and Symptoms of Liver Disease

Liver disease symptoms are often nonspecific early on, which makes diagnosis challenging. As disease progresses, more distinctive signs appear:

• Jaundice (icterus): Yellow discoloration of the skin, whites of the eyes, and gums. This is caused by bilirubin accumulating in the blood and tissues. Jaundice is one of the most recognizable — and serious — signs of liver disease.
• Lethargy and weakness: Profound fatigue is almost universal. Affected cats spend most of their time sleeping and show little interest in play or interaction.
• Loss of appetite (anorexia): Often the earliest sign. A cat that suddenly stops eating or shows dramatically reduced interest in food warrants attention.
• Vomiting and nausea: Bile acid abnormalities and toxin accumulation cause gastrointestinal upset.
• Weight loss: Rapid in severe cases due to both reduced intake and the liver's impaired ability to process nutrients.
• Abdominal swelling: Ascites (fluid in the abdomen) can develop in advanced liver failure due to reduced albumin production and portal hypertension.
• Neurological signs: Hepatic encephalopathy occurs when the brain is affected by toxins the liver can no longer clear. Signs include circling, head pressing, seizures, blindness, and disorientation.
• Excessive thirst and urination: Seen in some forms of liver disease.
• Orange or abnormally colored urine: Bilirubin excreted in urine turns it dark amber or orange.

Diagnosis

Diagnosing liver disease requires a combination of tests. Blood chemistry panels reveal elevated liver enzymes (ALT, AST, ALP, GGT) and bilirubin, as well as low albumin and blood glucose in severe cases. A complete blood count may show anemia or abnormal white cells. Bile acid stimulation tests assess liver function directly.

Abdominal ultrasound is invaluable for visualizing liver size, texture, and architecture, and for identifying masses or biliary abnormalities. However, ultrasound appearance cannot distinguish between hepatic lipidosis, cholangitis, and lymphoma — a liver biopsy (obtained by ultrasound-guided fine-needle aspiration or surgical core biopsy) is required for a definitive diagnosis and is essential for guiding treatment.

Treatment

Treatment is highly dependent on the underlying cause. Across nearly all forms of liver disease, however, supportive care is foundational:

Nutritional support is the most urgent priority, especially in hepatic lipidosis. If the cat will not eat voluntarily, placement of an esophagostomy or nasogastric feeding tube is necessary to deliver calories. Force feeding by syringe is stressful and inadequate. Tube feeding until the cat resumes voluntary eating on its own is the standard of care and can be life-saving.

Fluids and electrolytes are given intravenously to correct dehydration, hypokalemia (low potassium), and hypoglycemia.

Vitamin K is supplemented because the liver produces clotting factors that depend on it. Cats with liver disease may bleed abnormally.

S-Adenosylmethionine (SAMe) and milk thistle (silymarin) are hepatoprotective supplements with evidence supporting their use in feline liver disease. They help protect liver cells from oxidative damage. Many veterinarians recommend them as adjuncts to primary treatment.

For cholangitis, antibiotics (typically amoxicillin-clavulanate or enrofloxacin) are used for the neutrophilic form, while prednisolone is used for the lymphocytic form. For PSS, surgical correction (ameroid constrictor or suture ligation) is often curative in congenital cases.

Diet in Liver Disease

Contrary to older thinking, protein restriction is not recommended for most cats with liver disease. Cats require high-quality, digestible protein; malnutrition worsens outcomes significantly. The goal is highly digestible, balanced nutrition. Prescription liver diets or recovery diets with good palatability are preferred. Small, frequent meals reduce the metabolic burden on the liver. In hepatic encephalopathy, the branched-chain amino acid profile of the diet becomes more important, and your vet may guide specific formulations.

Prognosis

Hepatic lipidosis, caught before severe deterioration, carries a good prognosis — survival rates of 60–90% are reported with aggressive nutritional support. Cholangitis managed appropriately often achieves long-term remission. PSS corrected surgically can result in a normal life. Hepatic lymphoma prognosis depends on the form — alimentary low-grade lymphoma can be managed for years, while high-grade lymphoma carries a guarded short-term outlook.

References

1. Center SA. "Feline hepatic lipidosis." Veterinary Clinics of North America: Small Animal Practice. 2005;35(1):225-269. PMID: 15627635
2. Twedt DC, et al. "Evaluation of fluorescence in situ hybridization for the detection of Helicobacter in feline gastric tissue." Journal of Feline Medicine and Surgery. 2014;16(2):109-117. PMID: 23943810