Hepatic Lipidosis (Fatty Liver) in Cats: Causes & Treatment

Hepatic lipidosis, often called fatty liver disease, is one of the most common serious liver diseases in cats. It happens when large amounts of fat move into the liver and build up inside liver cells. Once enough fat accumulates, the liver cannot do its normal jobs well, including processing nutrients, handling toxins, and helping with digestion.

This condition is especially common after a cat stops eating or eats far less than usual for several days. Overweight cats are at higher risk, but cats at many body sizes can develop it. In more than 90% of cases, hepatic lipidosis is considered secondary, meaning another problem came first and triggered the appetite loss. That may include pancreatitis, diabetes, kidney disease, cancer, hyperthyroidism, stress, or another liver or digestive disorder.

For pet parents, the key point is this: a cat that is not eating is never something to watch for long at home. Hepatic lipidosis can start developing quickly, and early treatment gives your cat the best chance of recovery. Many cats do well when care begins promptly and nutritional support is started before liver failure becomes more severe.

Hepatic lipidosis usually develops after a period of poor appetite or anorexia. When a cat stops eating, the body starts moving stored fat to the liver for energy. Cats are not very good at handling this sudden fat shift, so the liver can become overloaded with triglycerides. That buildup interferes with normal liver function.

Cats who are overweight are at especially high risk, but obesity is not the only cause. Common triggers include stressful life changes like moving, boarding, a new pet, or a sudden diet change. Medical problems that reduce appetite are also common triggers, including pancreatitis, inflammatory bowel disease, diabetes mellitus, hyperthyroidism, kidney disease, cancer, cholangitis or other liver disease, and severe dental or mouth pain.

In many cats, hepatic lipidosis is not the first disease but the consequence of another illness. That is why your vet usually looks for both the fatty liver itself and the reason your cat stopped eating in the first place. Finding that underlying cause can shape treatment choices and help your cat recover more fully.

Your vet will usually start with a physical exam, body weight history, and questions about appetite, vomiting, stress, and recent weight loss. Bloodwork is commonly used to look for liver changes, dehydration, electrolyte problems, and clues to other diseases. A urinalysis is also often part of the workup.

Abdominal ultrasound is commonly used because it helps your vet assess whether the liver looks diffusely abnormal and whether there may be another problem, such as pancreatitis, gallbladder disease, or a mass. Imaging alone cannot always confirm the diagnosis, but it is very helpful for narrowing the list.

A more definitive diagnosis is often made by collecting liver cells with a fine-needle aspirate, usually guided by ultrasound, or in some cases by biopsy. Your vet may also recommend additional tests to look for the underlying reason your cat stopped eating. That can include thyroid testing, pancreatic testing, infectious disease testing, or more advanced imaging, depending on your cat's history and exam findings.

The best prevention is to act early any time your cat's appetite drops. If your cat eats much less than normal for a day, especially if they are overweight, contact your vet promptly. Cats are not small dogs when it comes to fasting. Even a short period of poor intake can become serious.

Safe weight management matters too. If your cat needs to lose weight, work with your vet on a gradual plan rather than a sudden calorie cut or abrupt diet switch. Rapid weight loss increases risk. Keep meals consistent, make diet changes slowly, and monitor body weight over time instead of trying to force quick results.

Reducing stress can also help. Changes like moving, boarding, travel, new pets, or household disruption can trigger food refusal in some cats. During stressful periods, watch food intake closely and ask your vet for a plan if your cat is prone to stress-related appetite loss.

Prevention also means managing underlying disease early. Cats with diabetes, kidney disease, pancreatitis, hyperthyroidism, dental pain, or digestive disease should be monitored closely because these conditions can reduce appetite and set the stage for hepatic lipidosis. If your cat stops eating, vomits repeatedly, or starts losing weight, do not wait for it to pass on its own.