Cat Not Eating or Vomiting: When to Worry

Quick answer

If a cat vomits once, then eats normally and acts like itself, you can usually just keep a close eye on it at home. If it refuses food for 24 hours, vomits repeatedly, seems weak or hides, or shows any of the emergency signs below, it needs a vet the same day. Cats are not like dogs here. Going without food can quickly lead to a dangerous liver condition, so "waiting it out" for days is never safe.

Why not eating is serious in cats

Once a cat stops eating, its body starts breaking down fat for energy, and cats cope with this badly. The liver can get swamped with fat, a condition called hepatic lipidosis (fatty liver disease). It can set in after only a few days of poor eating and is more likely in overweight cats. It is treatable, but much easier to prevent than to fix, which is why vets take a cat going off its food more seriously than the same thing in many other animals.

Vomiting, regurgitation or a hairball?

Your vet will find it useful if you can describe exactly what you saw.

Take a photo of whatever comes up and note the time. "Three times since this morning, yellow fluid, no food since yesterday" tells a vet far more than "a few times".

Common causes

Vomiting and poor appetite are symptoms, not a diagnosis. The usual culprits:

• Eating too fast or a sudden food change. Vomiting often follows shortly after a meal.
• Hairballs, especially in long-haired breeds.
• Eating something they shouldn't. String, thread, hair ties, ribbon, tinsel, plastic or bones can cause a blockage. Never pull on a string you see in a cat's mouth or under its tail. It may be anchored inside and can do serious internal damage.
• Toxins. Lilies are the big one: every part, including pollen and vase water, can cause kidney failure in cats. Others are some household cleaners, human medicines and some insecticides, including dog flea products containing permethrin.
• Infections and parasites, particularly in kittens.
• Dental pain. A cat may be hungry yet stop eating because chewing hurts.
• Chronic illnesses such as kidney disease, an overactive thyroid, diabetes, pancreatitis, inflammatory bowel disease and some cancers. These turn up more in middle-aged and older cats and often bring gradual weight loss along with the vomiting.
• Stress. A house move, a new pet, building work or a change in routine can put a cat off its food for a short while.
• Urinary blockage. A male cat straining in the litter tray with little or no urine may also vomit and stop eating. This is an emergency.

What you can do at home (for a mild case)

This is only for a cat that is bright and alert and has vomited once or twice with nothing else worrying going on:

1. Take the food away for a short time (a few hours) so the stomach can settle, but leave fresh water down. Don't withhold food for long.
2. Offer a small amount of their usual food afterwards, or a bland food your vet recommends. Wet food warmed slightly is often more tempting.
3. Watch closely for the next 12–24 hours. Note eating, drinking, litter tray use, energy and any more vomiting.
4. Look around the home for anything chewed or missing: thread, elastic bands, plants, medication packets.
5. Don't give any human medicine or home remedies. Paracetamol is especially dangerous to cats.

If anything gets worse, or your cat still isn't eating normally by the next day, call the vet.

When to see a vet

Go to a vet immediately (emergency) if your cat:

• Is a male straining to urinate or passing little or no urine
• Has collapsed, is very weak, or has pale, grey or yellowish gums
• Is breathing with an open mouth or struggling to breathe
• Vomits blood (red or "coffee grounds") or has black, tarry stools
• Has a swollen, painful belly or cries when picked up
• May have eaten a lily, medicine, poison or string
• Is a kitten that is vomiting and has diarrhoea or is not eating

Book a same-day or next-day appointment if your cat:

• Has not eaten for 24 hours (sooner for kittens, older cats and overweight cats)
• Vomits more than two or three times in a day, or keeps vomiting after eating
• Is hiding, much quieter than usual, or not using the litter tray normally
• Has diarrhoea along with vomiting

Mention it at a routine visit soon if your cat:

• Vomits regularly, for example weekly, even if otherwise well. Plenty of cats do this, but it is not "normal" and can be an early sign of a chronic condition.
• Is losing weight, drinking more or urinating more.

What the vet may do

The vet will start by asking about the history and examining your cat: checking hydration, looking at the mouth and teeth, feeling the belly. Depending on what they find, they may suggest blood and urine tests, X-rays or ultrasound. Treatment depends on the cause. It might be fluids for dehydration, anti-nausea medication, appetite support or a diet change, or surgery if there's a blockage. Follow the dosing and instructions exactly, and go back if your cat isn't improving the way the vet expected.

Preventing future episodes

• Feed measured meals. For cats that gulp, try a slow feeder or puzzle feeder.
• Change diets gradually over about a week.
• Brush long-haired cats regularly so they swallow less hair.
• Keep string, thread, hair ties and small bits of plastic out of reach.
• Don't have lilies in a home with cats at all.
• Use only flea products labelled for cats (see our guide to fleas on cats).
• Book yearly check-ups, or twice-yearly for senior cats, so slow-developing conditions get caught early.

For the basics of feeding, litter and routine, see our cat care guide for beginners.