How quickly can hepatic lipidosis develop?

In obese cats, hepatic lipidosis can develop within 48–72 hours of anorexia. In cats of normal body weight it typically takes longer — 5–7 days or more — but it is not exclusively a disease of overweight cats. Any cat that stops eating for more than 48 hours should be seen by a vet. See signs it is time to call the vet for what to watch for.

Can hepatic lipidosis be treated?

Yes, but it requires intensive veterinary treatment. The cornerstone of treatment is nutritional support — often delivered through a feeding tube placed directly into the oesophagus or stomach. Fluid therapy, vitamin supplementation, and management of the underlying cause are also required. With prompt, aggressive treatment, survival rates are high (over 80% in some studies); without treatment, the condition is usually fatal.

How can I prevent hepatic lipidosis in my overweight cat?

Never put an overweight cat on a very low-calorie diet without veterinary supervision. Gradual weight loss at 0.5–1% of body weight per week is the safe target. If your cat stops eating during a weight-loss programme — even for one day — contact your vet immediately. Use our feeding calculator to establish an appropriate starting calorie target.

What causes a cat to stop eating?

Causes include: stress (moving home, a new pet, changes in routine), underlying illness (dental pain, nausea, infection), dietary changes made too abruptly, and environmental changes. See our guide on when to call the vet if your cat has not eaten for more than 24 hours.

Hepatic Lipidosis — Cat Glossary

Definition

Hepatic lipidosis (also called feline fatty liver syndrome) is the most common liver disease in cats. It occurs when a cat stops eating and the body begins mobilising fat stores to compensate. In cats, the liver rapidly accumulates fat during this process — a consequence of cats' unusual metabolic reliance on fat and protein for energy. When fat accumulates faster than the liver can export it, liver function deteriorates. Without intervention, the condition progresses to liver failure.

Why cats are uniquely vulnerable

Unlike dogs and humans, cats have limited ability to downregulate fat mobilisation during food restriction. Their livers lack sufficient enzyme activity to safely process large amounts of circulating free fatty acids. This makes the period of anorexia that is tolerable in other species genuinely dangerous in cats — particularly obese cats, who have larger fat reserves to mobilise.

The condition was first described in detail in the veterinary literature in the 1970s and is well-established in the Merck Veterinary Manual. It is one of the key reasons veterinary guidance emphasises that cat diets should never be changed abruptly and that cats should not undergo rapid weight loss.

Causes and risk factors

Hepatic lipidosis is always secondary — it is caused by something else stopping the cat from eating. Common underlying causes include:

Stress events: house move, new cat in household, owner absence, environmental change
Dental pain or oral disease making eating painful
Underlying illness causing nausea: pancreatitis, inflammatory bowel disease, kidney disease
Abrupt diet change (cat refuses new food)
Post-surgical anorexia

Obese cats are at highest risk because they have more fat to mobilise and are more likely to develop anorexia during illness. This is why crash diets in overweight cats are dangerous — even a well-intentioned rapid calorie restriction can trigger the same cascade. See our guide on how much to feed your cat for safe weight management principles.

Signs

Anorexia (not eating) — often the first and only early sign
Rapid weight loss
Lethargy and weakness
Vomiting
Jaundice (yellowing of the skin, gums, and whites of the eyes) — indicates advanced disease
Drooling or difficulty swallowing

A cat showing any combination of these signs needs a vet call now. Our full guide to signs it is time to call the vet lists the emergency indicators by urgency.

Definition

Why cats are uniquely vulnerable

Causes and risk factors

Signs

Frequently asked questions