Why Is My Cat Not Eating? 6 Causes & When to Call a Vet

Updated 30 July 2026 · Reviewed against Cats Protection, PDSA and International Cat Care guidance

A cat that turns its nose up at dinner is worrying — and you're right to pay attention. Cats are creatures of habit, and a missed meal is often the very first sign that something is wrong, from a stressful week at home to kidney disease. This guide walks through the six most common causes, how to judge whether it's an emergency, and what you can safely try at home while you decide.

How Long Can a Cat Go Without Eating? (The 24-Hour Rule)

Here is the single most important fact in this guide: a cat that has eaten nothing for more than 24 hours needs to see a vet. Not tomorrow, not after the weekend — within a day.

The reason is a quirk of feline biology. When a cat stops eating, its body starts breaking down fat for energy. But a cat's liver is not built to handle a sudden flood of fat. Within as little as two or three days of not eating, fat can accumulate in the liver and cause hepatic lipidosis (fatty liver disease) — a serious, sometimes fatal condition that requires aggressive treatment. Overweight cats are most at risk, which feels deeply unfair but is important to know.

Dogs can safely skip meals for a day or two. Cats cannot. So while one refused breakfast is fine to watch with a calm eye, a full 24 hours without food is your hard line — call your vet.

6 Common Reasons Cats Stop Eating

1. Stress

Cats find change genuinely unsettling. Moving house, a new kitten or puppy, a baby, visitors, building work, fireworks season, or you being away on holiday can all switch off a cat's appetite. This is the most common cause of a short hunger strike in an otherwise healthy cat — and the one most likely to fix itself within a day once the household settles.

2. Dental pain

Gingivitis, broken teeth and feline tooth resorption (painful lesions where the tooth body dissolves — surprisingly common in UK cats) can make chewing miserable. Classic signs: your cat approaches the bowl with enthusiasm, takes one bite, then drops food, chews on one side, or walks away. You may also notice dribbling or bad breath.

3. Food aversion

Has anything about the food itself changed? A new brand, a new flavour, a "new and improved" recipe from the same brand, or a bag of biscuits that has been open for six weeks and gone stale. Cats also learn to avoid a food they once ate shortly before feeling sick — a reasonable survival strategy, even if the food wasn't to blame.

4. Illness

Loss of appetite is one of the earliest signs of most feline illnesses. The big ones UK vets see in middle-aged and older cats are chronic kidney disease (CKD) and hyperthyroidism (an overactive thyroid — these cats often eat ravenously at first, then go off food as the disease progresses). Nausea from almost any cause — pancreatitis, gut inflammation, infections — will also stop a cat eating. This is why the 24-hour rule matters: appetite loss is a symptom, not a diagnosis.

5. Ageing

Senior cats experience a gentle decline in smell and taste, and since cats decide whether food is worth eating mostly by scent, dinner simply becomes less interesting. Older cats may also have arthritis that makes bending to a floor-level bowl uncomfortable. Ageing explains a gradual, mild decline in enthusiasm — it should never explain a cat that stops eating entirely. That still needs a vet.

6. Vaccination side effects

A mild, short-lived dip in appetite (along with a quiet day and maybe slight soreness) is a recognised, normal reaction in the 24–48 hours after a vaccination. If your cat has just been to the vet for its annual jabs and skips a meal, this is usually why. Appetite should bounce back within a day or two — if it doesn't, call the practice.

How to Tell If It's an Emergency

Not eating on its own for a few hours is rarely an emergency. Not eating plus another symptom changes the picture completely.

When in doubt, ring your vet practice — a two-minute phone call costs nothing, and UK vet nurses are excellent at triaging over the phone. Out of hours, the PDSA and Blue Cross can point you to emergency cover.

What You Can Try at Home

If your cat is otherwise bright and you're within the 24-hour window, these six tactics are safe to try:

• Warm the food. Ten seconds in the microwave (stir well, check it's not hot) releases aroma — and cats eat with their nose first.
• Switch to a shallow, wide bowl. Deep bowls press on a cat's whiskers, and some cats find that genuinely uncomfortable ("whisker fatigue"). A saucer or flat plate works just as well.
• Feed somewhere quiet. A calm corner away from the litter tray, the washing machine and the dog. Anxious cats eat better with an escape route and no audience.
• Change the texture. Dry-food-only cats often find pâté or gravy wet food more tempting, especially if nausea or dental pain is involved.
• Offer a little by hand. A few pieces of cooked plain chicken or a favourite treat from your fingers can restart interest — it also tells you the appetite isn't gone entirely.
• Ask your vet about appetite stimulants. Medications such as mirtazapine can be very effective, but they must come from your vet after a check-up — never dose your cat yourself.

Breed-Specific Notes

British Shorthair. The UK's favourite pedigree is famously food-motivated, so a British Shorthair refusing food is a bigger red flag than it would be in other breeds. They are also prone to dental disease, so ask your vet to check their teeth first.

Siamese. Notoriously fussy, and more prone to food sensitivities than most breeds. A Siamese that turns down dinner may simply be registering a complaint about the menu — but the 24-hour rule still applies.

Persian. Flat faces make picking food up physically awkward. Persians often eat slowly and messily from deep bowls, and a wide, shallow dish can transform mealtimes. If your Persian seems keen but gives up halfway, try changing the bowl before worrying about the appetite.

Frequently Asked Questions