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Why Is My Cat Not Eating? Causes and What to Do

Unlike dogs, cats cannot safely go without food for extended periods. A cat that has not eaten for 24–48 hours is at risk of a serious condition called hepatic lipidosis (fatty liver disease), regardless of the reason for the food refusal. This makes inappetence in cats more medically urgent than in most other species.

Why Cat Inappetence Is a Medical Concern

Cats have a unique metabolic vulnerability: when they stop eating — for any reason — their bodies begin mobilising fat stores for energy. Unlike most mammals, cats process this fat inefficiently, causing fat to accumulate in the liver and impairing its function. This condition, hepatic lipidosis (fatty liver syndrome), can develop within 24–72 hours of total food refusal in some cats, particularly obese cats.

Left untreated, hepatic lipidosis progresses to liver failure and can be fatal. This means that a cat's inappetence should never be assumed to be trivial — even if the apparent cause seems minor (a new food, stress, a house move). If your cat has not eaten for more than 24 hours, contact your vet.

The PDSA and RCVS both recommend that owners seek veterinary advice promptly for a cat that stops eating, as the underlying cause — whatever it is — is always more easily treated before hepatic lipidosis develops as a complication.

Common Causes of Food Refusal in Cats

The range of causes of inappetence in cats is wide. Common causes include: dental pain — the PDSA estimates that 70% of cats over three have dental disease, and oral pain is one of the most frequent causes of reduced appetite; respiratory infections — cats use their sense of smell to identify food, and a blocked nose from a cat flu infection can make food unappealing; nausea — from kidney disease, liver disease, pancreatitis, or medication; stress — from environmental changes, a new pet or baby, construction noise, or any significant disruption to routine; and gastrointestinal problems such as inflammatory bowel disease, foreign body ingestion, or constipation.

In older cats, the conditions most frequently associated with inappetence are chronic kidney disease, hyperthyroidism (although this more often causes increased appetite initially), dental disease, cancer, and cardiac disease. These conditions become increasingly common over the age of eight and are why 6-monthly health checks for senior cats are recommended.

Some cats are genuinely finicky — they may refuse food simply because it has been changed, is served at a different temperature, is in an unfamiliar bowl, or is perceived as 'stale'. However, behavioural fussiness should only be considered as a diagnosis once medical causes have been ruled out.

When to Contact the Vet

Contact your vet if your cat: has not eaten for more than 24 hours; is eating significantly less than usual for 48 hours or more; is also vomiting, lethargic, or hiding; is losing weight; has always been a good eater and has suddenly gone off food; or has a known health condition (particularly kidney disease, diabetes, or hyperthyroidism) that may be affecting appetite.

Do not wait and see for more than 24 hours in a cat that is not eating — the risk of hepatic lipidosis developing makes prompt veterinary assessment important regardless of how mild the cause seems. Your vet can assess whether the cat is dehydrated, identify any obvious cause (such as a mouth ulcer or dental pain), and recommend appropriate management.

If your cat is also showing signs of jaundice (yellow tinge to the gums, whites of the eyes, or inner ear flap), this suggests the liver is already affected and is an urgent veterinary emergency.

Encouraging a Cat to Eat

While waiting for or following a vet appointment, there are some strategies for encouraging a reluctant eater. Warming food slightly (to body temperature, around 38°C) enhances aroma and can stimulate interest in food — this is particularly helpful for cats with a stuffy nose from a respiratory infection. Offering small amounts of a strong-smelling, palatable food (such as tuna in spring water, or a specialist convalescent diet) can be helpful.

In some cases, your vet may prescribe appetite stimulants such as mirtazapine (available as a transdermal gel applied to the ear flap in cats) or cyproheptadine. These are prescription medications and should only be used under veterinary guidance. If a cat is unable or unwilling to eat voluntarily for more than 2–3 days, your vet may recommend placement of a feeding tube — this sounds dramatic but is often a straightforward, life-saving procedure that allows nutritional support while the underlying condition is treated.

Do not attempt to force-feed liquid food into a cat's mouth without veterinary guidance — this carries a significant risk of aspiration pneumonia if the cat does not swallow cooperatively.

Comparing Vet Costs for Inappetent Cats

Investigating a cat that has stopped eating typically involves a physical examination (£40–£65), blood tests (£80–£150) including kidney function, liver enzymes, thyroid levels, and blood glucose, and possibly urine analysis and imaging. If hospitalisation for fluid support and tube feeding is needed, costs rise considerably — typically £300–£800 or more per night depending on the severity of the condition.

Knowing the costs you are likely to face, and finding a vet practice that is transparent about pricing, helps you plan and make informed decisions. CompareMyVet at app.comparemyvet.uk provides price comparisons for local vet practices currently across Brighton & Hove, and is expanding across the UK.

If your cat is diagnosed with a chronic condition requiring long-term medication — such as kidney disease, hyperthyroidism, or inflammatory bowel disease — ask for a written prescription under the March 2026 CMA reforms so you can source medication at a more competitive price from a registered online pharmacy.