Why Won't My Cat Eat? Appetite Loss and Hepatic Lipidosis in Cats

What you need to know

Cats are metabolically unique in a way that makes food refusal genuinely dangerous — far more so than in dogs or humans. When a cat stops eating, even briefly, the body begins mobilizing fat reserves to compensate. In cats, this process can overwhelm the liver's capacity to process fat, causing it to accumulate inside liver cells and leading to a condition called hepatic lipidosis — also known as fatty liver disease.

Hepatic lipidosis is one of the most common serious liver diseases in cats, and it can begin developing after several days of markedly reduced food intake, particularly in overweight cats. Without treatment, it can be fatal. The earlier it is identified and the earlier nutritional support is started, the better the outcome.

Why cats stop eating: common causes

Appetite loss in cats — called anorexia or inappetence — is always a symptom of something else. The underlying cause needs to be identified. Common reasons include:

Medical causes

• Pancreatitis — One of the most common causes of sudden appetite loss in cats (see Guide 23)
• Inflammatory bowel disease (IBD) — Chronic nausea from GI inflammation suppresses appetite
• Chronic kidney disease (CKD) — Uremic toxins cause nausea and appetite suppression
• Hyperthyroidism — Paradoxically, some hyperthyroid cats have reduced appetite despite the condition typically increasing it
• Dental disease — Mouth pain from tooth resorption, gingivitis, or abscesses is a very common and underrecognized cause of appetite loss
• Upper respiratory infection — Cats rely heavily on smell to find food appetizing; a blocked nose makes food unappealing
• Diabetes mellitus
• Cancer — GI lymphoma, oral tumors, and other malignancies
• Pain from any source — Arthritis, injury, post-surgical discomfort
• Medications — Some drugs suppress appetite as a side effect

Behavioral and environmental causes

• Stress — Moving, new pets, new people, schedule changes, or litter box issues
• Food aversion — A cat that felt nauseous while eating a particular food may refuse that food going forward
• Food change — Abrupt diet changes can cause refusal
• Bowl preference — Some cats dislike deep bowls that touch their whiskers (whisker fatigue); others prefer certain materials

What is hepatic lipidosis?

When a cat stops eating, the body mobilizes fat from peripheral stores and sends it to the liver for energy processing. In cats, this fat transport system can easily overwhelm hepatic capacity — fat accumulates within liver cells faster than it can be metabolized, impairing liver function. The liver essentially becomes infiltrated with fat, reducing its ability to perform its many critical roles.

Left untreated, hepatic lipidosis progresses to liver failure, jaundice, hepatic encephalopathy (neurological signs from toxin accumulation), and death. With aggressive nutritional support, recovery rates are high — but treatment must begin early.

Signs of hepatic lipidosis

How it is diagnosed

• Bloodwork — Elevated liver enzymes (ALT, ALP), bilirubin, and sometimes low albumin and potassium
• Urinalysis — Bilirubin in the urine may be an early indicator
• Abdominal ultrasound — The liver appears hyperechoic (brighter than normal) due to fat infiltration
• Fine needle aspirate or biopsy — Definitive confirmation; shows fat-filled hepatocytes under the microscope

Treatment: nutrition is the cure

The treatment for hepatic lipidosis is nutritional support — getting adequate calories into the cat so the liver can begin clearing the accumulated fat. This is one of the few conditions where the treatment is as straightforward as the diagnosis is urgent:

• Feeding tube placement — An esophagostomy (E-tube) or nasogastric tube allows the owner to feed the cat at home; cats tolerate E-tubes remarkably well and most owners manage them confidently after instruction
• Appetite stimulants — Mirtazapine (oral or transdermal) can stimulate appetite in some cats; used alongside, not instead of, nutritional support
• IV fluid therapy — Corrects dehydration and electrolyte imbalances
• Potassium supplementation — Commonly needed; low potassium (hypokalemia) is a frequent complication
• Treating the underlying cause — Identifying and managing whatever caused the anorexia is essential to prevent recurrence

Recovery from hepatic lipidosis takes weeks of nutritional support. Patience and commitment to tube feeding are essential. With dedicated care, many cats make a full recovery.

Common myths

Myth: "If I just wait, my cat will eat when she's hungry enough"

This approach is genuinely dangerous in cats. Unlike dogs and humans, cats do not reliably return to eating when hunger intensifies — and the longer a cat goes without food, the greater the hepatic lipidosis risk. By the time obvious jaundice or neurological signs appear, the condition may be advanced. Early intervention is always better than waiting.

Myth: "Tube feeding is cruel or traumatic for the cat"

This is a common concern that veterinary experience consistently contradicts. Cats typically tolerate esophagostomy tubes very well — most eat and behave normally with the tube in place, and owners often report that their cat seemed more comfortable once nutrition was restored. The discomfort of the tube is far less than the suffering of progressive starvation and liver failure.