CONDITION

Hepatic Lipidosis in Cats

Hepatic lipidosis is a condition in which fat accumulates rapidly in the liver, impairing the organ's ability to function. It develops when a cat stops eating for a period of days — often as few as two to three days of complete anorexia, though it can occur over a longer window of two to seven days. The condition tends to develop more quickly in cats who were overweight before they stopped eating, though any cat who has not eaten for several days can be affected. Owners most commonly notice a cat who has stopped eating, appears lethargic or weak, and may develop a yellowed colour to the whites of the eyes, gums, or skin — a sign that liver function has become compromised. The earlier lack of appetite may have followed a stressful event, illness, or change in routine, and the cat's condition often declines noticeably over the course of days. This page explores the outward signs an owner may observe, the metabolic process that leads to fat accumulation in the liver, the investigations used to confirm the diagnosis and assess severity, and the approaches used to support recovery and restore normal liver function.

Why this matters now

Hepatic lipidosis tends to develop in middle-aged cats, with most cases occurring around seven years of age, though cats of any age can be affected. Obese or overweight cats carry considerably higher risk, particularly when they experience a period of stress, illness, or environmental change that disrupts their normal eating pattern. In more than 85 per cent of cases, an underlying condition — such as pancreatitis, inflammatory bowel disease, diabetes, or respiratory illness — triggers the initial loss of appetite, though sometimes the catalyst may be a household change, the arrival of a new pet, or accidental confinement.

The condition often unfolds over several days to a few weeks. A cat may stop eating or eat very little, and during this period fat stores begin to mobilise silently. Within days, the liver becomes overwhelmed by the incoming fat, and jaundice, weakness, and deepening reluctance to eat typically emerge. The pace can vary; some cats deteriorate gradually, others more quickly, and the trajectory often reflects both the severity of fat accumulation and the nature of any underlying trigger.

Signals & patterns

Early signals

Reduced or absent appetite

The cat may begin to turn away from food, eat smaller portions, or stop eating entirely. This change often follows a stressful event, illness, or alteration in routine, and may be subtle at first before becoming more pronounced over several days.

Quiet or withdrawn behaviour

An owner may notice that the cat becomes less interactive, spending more time resting in secluded spots and showing less interest in usual activities. This shift in demeanour can reflect the early metabolic strain on the body.

Weight loss despite prior obesity

Even a cat that was recently overweight may begin to lose body condition noticeably over the course of a week or two. The loss often appears disproportionate to the brief period of reduced intake, reflecting the mobilisation of fat stores.

Vomiting or occasional nausea

Some cats may vomit intermittently or show signs of nausea, such as lip-licking, drooling, or reluctance to approach food. These signs can accompany the early stages of liver dysfunction.

Later signals

Yellow discolouration of skin or mucous membranes

Jaundice often becomes visible in the whites of the eyes, the gums, or the inside of the ears as the liver's capacity to process bilirubin diminishes. This yellowing tends to deepen as the condition progresses and may be one of the more striking changes an owner observes.

Marked weakness or difficulty moving

The cat may struggle to jump, walk unsteadily, or spend long periods lying down without moving. This profound lethargy reflects both the metabolic disturbance and the muscle wasting that can accompany prolonged anorexia.

Increased drooling or lip smacking

Excessive salivation, sometimes accompanied by repetitive swallowing or lip movements, may occur as nausea intensifies. This can signal worsening hepatic dysfunction and the accumulation of metabolic byproducts.

Click to read about the biological mechanisms

How this is usually investigated

The investigation of suspected hepatic lipidosis begins with a careful history of recent eating patterns, weight changes, and any triggering events such as illness, stress, or household disruption. Physical examination often reveals jaundice in the gums, sclera, or inner ear pinnae, along with signs of dehydration and sometimes hepatomegaly. Blood tests form the core of the diagnostic assessment, while imaging helps confirm hepatic changes and rule out other causes of liver disease or anorexia.

Chemistry panel

Purpose: Blood biochemistry typically shows marked elevation of bilirubin (often total bilirubin above 50–100 µmol/L), variable increases in liver enzymes, and may reveal low albumin, elevated blood glucose, or electrolyte disturbances. Alkaline phosphatase (ALP) tends to be markedly elevated, while alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are often raised but may be only mildly so.
Considerations: A characteristic pattern in hepatic lipidosis is very high ALP with a disproportionately normal or only mildly elevated GGT, helping distinguish the condition from cholangitis or other hepatobiliary diseases where GGT rises proportionally with ALP. The degree of bilirubin elevation correlates loosely with severity, but individual variation is wide.

Complete blood count

Purpose: A full blood count may show anaemia (often non-regenerative), and sometimes a stress leucogram or mild leucocytosis. It helps rule out concurrent infection or inflammatory disease that might complicate the picture.
Considerations: The findings are often non-specific, and a normal blood count does not exclude hepatic lipidosis. The value lies more in identifying complicating factors than in confirming the diagnosis itself.

Abdominal ultrasound

Purpose: Ultrasound examination reveals a diffusely hyperechoic (bright) liver, reflecting the widespread fat accumulation within hepatocytes. The appearance is often described as uniformly increased echogenicity compared to the falciform fat or renal cortex.
Considerations: The hyperechoic liver is highly suggestive but not entirely specific; other infiltrative conditions can produce similar changes. Ultrasound also allows assessment of biliary tract patency, detection of concurrent pancreatitis, and evaluation of other abdominal organs that might be contributing to anorexia.

Cytology

Purpose: Fine-needle aspiration of the liver, followed by cytological examination, typically shows hepatocytes distended with clear vacuoles representing lipid droplets. Staining with Sudan or Oil Red O can confirm the vacuoles contain fat.
Considerations: Cytology is minimally invasive and often diagnostic when the classic fat-laden hepatocytes are seen, but it samples only a small area and does not provide architectural information. Coagulopathy should be assessed before aspiration, as hepatic lipidosis can impair clotting factor synthesis.

Histopathology

Purpose: Liver biopsy provides definitive diagnosis by demonstrating the extent of hepatocellular lipid accumulation and ruling out concurrent hepatobiliary disease such as cholangitis, lymphoma, or chronic hepatitis. It also allows grading of the lipid infiltration and assessment of any fibrosis or inflammation.
Considerations: Biopsy carries higher risk in a debilitated, coagulopathic cat and is often reserved for cases where the diagnosis remains uncertain after less invasive testing, or where concurrent disease is suspected. In many cases, the combination of history, biochemistry, and ultrasound is sufficient to proceed with treatment.

Options & trade-offs

Management of hepatic lipidosis centres on restoring nutritional intake to halt fat mobilisation, reverse hepatocellular lipid accumulation, and allow liver regeneration. Because the nausea and hepatic dysfunction prevent voluntary eating in most cases, feeding tube placement is the mainstay of treatment, combined with correction of fluid and electrolyte imbalances, treatment of any underlying or concurrent illness, and supportive care for complications such as coagulopathy or hepatic encephalopathy. The combination and intensity of interventions vary with the individual cat's condition and the owner's circumstances.

Oesophagostomy or nasogastric tube feeding

Placement of a feeding tube — most often an oesophagostomy tube placed under brief anaesthesia, or a nasogastric tube placed without sedation — allows delivery of a controlled volume of liquid diet directly into the gastrointestinal tract, bypassing the cat's aversion to eating. Feeding begins at small volumes and is gradually increased over several days to meet the cat's calculated caloric requirement, typically using a high-protein, energy-dense liquid or blended recovery diet. Tube feeding continues for weeks to months until the cat begins eating voluntarily and liver function normalises.

Trade-offs: Oesophagostomy tubes are well tolerated by most cats and allow home management, but require owner commitment to multiple daily feedings, tube care, and monitoring. Nasogastric tubes avoid anaesthesia but are less comfortable, more likely to be dislodged, and suitable only for short-term use. Refeeding too quickly can precipitate refeeding syndrome, a potentially serious electrolyte disturbance, so careful volume escalation and monitoring of phosphate, potassium, and magnesium are necessary.

Intravenous fluid therapy and electrolyte correction

Cats with hepatic lipidosis are often dehydrated and may have significant electrolyte abnormalities including hypokalaemia, hypophosphataemia, and hypomagnesaemia. Intravenous fluids restore hydration and allow correction of these imbalances before and during the early stages of nutritional support. Supplementation of potassium, phosphate, and magnesium is guided by repeated blood monitoring.

Trade-offs: Fluid therapy stabilises the cat and reduces the risk of refeeding syndrome, but requires hospitalisation or frequent veterinary visits for administration and monitoring. Over-enthusiastic fluid administration in a cat with low albumin can contribute to oedema or pleural effusion, so rates and volumes are adjusted to the individual.

Appetite stimulants and anti-nausea medication

Medications such as maropitant (an anti-emetic) and mirtazapine (which has anti-nausea and appetite-stimulating effects) are often used to reduce nausea and encourage voluntary food intake. These drugs can make the cat more comfortable and, in mild or recovering cases, may help restart eating without a feeding tube. Maropitant is given daily, while mirtazapine is typically given every two to three days in cats due to its long half-life.

Trade-offs: Appetite stimulants alone rarely restore adequate caloric intake in established hepatic lipidosis, where the degree of liver dysfunction and nausea usually overwhelms pharmacological intervention. They are most useful as adjuncts to tube feeding or in very early, mild cases. Mirtazapine can cause sedation or, paradoxically, hyperactivity in some cats.

Treatment of underlying or concurrent disease

Identifying and addressing any condition that triggered the anorexia — such as pancreatitis, inflammatory bowel disease, dental pain, hyperthyroidism, or chronic kidney disease — is essential, as the hepatic lipidosis will not resolve if the underlying cause continues to suppress appetite. Treatment is tailored to the specific diagnosis and may include antibiotics, anti-inflammatories, analgesics, or management of chronic illness.

Trade-offs: Concurrent disease can complicate both diagnosis and treatment, and some conditions (such as pancreatitis) may worsen temporarily during early nutritional support. The response to treatment of the underlying trigger is variable, and in some cases no clear trigger is identified, requiring reliance on nutritional support alone.

Vitamin and amino acid supplementation

Cats with prolonged anorexia can become deficient in water-soluble vitamins (particularly B vitamins including thiamine and cobalamin) and certain amino acids such as taurine and arginine, which cats cannot synthesise in adequate quantities. Supplementation of B vitamins is often given parenterally or added to tube feeds, and taurine may be supplemented orally or in the diet.

Trade-offs: Vitamin and amino acid deficiencies develop over days to weeks, so supplementation is more relevant in cats with prolonged illness or delayed presentation. Thiamine deficiency can produce neurological signs, and arginine deficiency can worsen hepatic encephalopathy, so empirical supplementation during tube feeding is common practice even when deficiency has not been documented.

Common misconceptions

Misconception:

"A cat that has stopped eating for a few days will start again on its own once it gets hungry enough."

Reality:

In cats, prolonged anorexia triggers metabolic changes that perpetuate the loss of appetite rather than reversing it. The liver dysfunction caused by fat accumulation produces nausea and malaise that actively suppress hunger, creating a cycle where the longer the cat goes without eating, the less able it becomes to start again voluntarily. External nutritional support is usually necessary to break this cycle.

Misconception:

"Hepatic lipidosis is usually fatal even with treatment."

Reality:

With prompt, aggressive nutritional support via feeding tube, survival in cats with hepatic lipidosis is approximately 80–90 per cent. The liver has substantial regenerative capacity, and once nutritional intake is restored and fat mobilisation halts, hepatocellular lipid can be metabolised and liver function can recover over weeks to months. The prognosis is most favourable when treatment begins early and any underlying trigger is addressed.

Misconception:

"Feeding tubes are only used as a last resort when nothing else has worked."

Reality:

Feeding tube placement is the primary treatment for hepatic lipidosis and is most effective when instituted early, before severe complications such as coagulopathy or hepatic encephalopathy develop. Delaying tube placement while attempting to coax voluntary eating often allows the disease to progress, worsening the prognosis and prolonging recovery. Tubes are a tool for restoring nutrition efficiently, not a measure of failure.

Related conditions

Understanding the metabolic factors that predispose a cat to hepatic lipidosis — particularly body condition and the unique feline response to fasting — may inform conversations about weight management and the significance of even short periods without food in overweight cats. The page on feline obesity within the Metabolic Health section explores the physiological consequences of excess body weight and the considerations around gradual weight reduction. For cats with concurrent conditions such as pancreatitis or inflammatory bowel disease that may have triggered the episode, the relevant pages within the Digestive Health section describe how these conditions interact with appetite and recovery.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS