Guide to Human Foods That Are Toxic to Cats
Poisons and toxins are substances that have an adverse effect on the body, even a very mild effect. Cats can be exposed by ingesting (eating) a toxic substance, inhaling (breathing) it, or absorbing it through the skin.
When a cat is poisoned, a wide range of symptoms may occur, from minor skin irritation to death. Luckily, some toxins have antidotes which are specific medications given to counteract a specific poison(antidotes). Toxins that do not have a specific antidote are treated with supportive care through medications and supplements to correct symptoms and keep any more of the toxin from being absorbed into the system.
Poisoning in cats is less common than in dogs, as cats tend to be more particular about what they encounter. Still, even with cats, poisonings occur often.
Published October 2025 | Review date October 2028 | This advice is for UK pets only and is not a replacement for seeing a vet
Common Human Foods That Are Toxic to Cats
Onions, garlic, chives, and leeks: cats are the most sensitive of all animal species to toxicity from ingestion of onions and garlic. Cats have been reported to show signs of toxicity not only with fresh, raw produce but also foods containing dehydrated flakes, powders, and dry onion soup mixes. Signs of toxicity in cats have been reported with an ingestion of less than a teaspoon of cooked onions. This toxin causes your cat to develop possibly life-threatening haemolytic anaemia, a condition in which your cat’s body destroys its own red blood cells, resulting in anaemia (low red blood cell count). Your cat might require a blood transfusion. Signs of anaemia develop within 24 hours.
Chocolate: contains small amounts of caffeine and large amounts of a substance called theobromine. Together they are very dangerous to cats. Chocolate toxicity in cats becomes more severe as the amount of cocoa increases.
Caffeine: is a stimulant and is toxic to cats and the same stimulant effects that help humans stay awake can cause toxicity in cats.
Xylitol: is a sugar substitute and toxicity symptoms occurring when cats ingest larger amounts of this known toxin.
Grapes and raisins: while the toxic principle in grapes is not completely understood, any ingestion of grapes by a cat is considered potentially toxic and should be treated as an emergency. Grape/raisin toxicity can cause life-threatening kidney damage and/or kidney failure.
Food mould: is a fungus that grows on aging food. It is usually visible to the naked eye and will make your cat sick if ingested. Cats are exposed to this toxin when they eat mouldy food directly out of the household rubbish or find it outside. They also can ingest it through a compost pile or from mouldy nuts or fruits that have fallen from trees. The toxin can also be inhaled if your cat comes into close contact with it, even without eating the fungus. These inhaled fungal toxins can cause damage to the lungs as well as difficulty breathing, rapid breathing, and elevated body temperature.
Signs of Poisoning in Your Cat and What to Do
Signs that might show that your cat has been poisoned include:
twitching and fitting
breathing difficulties
shock or collapse
inflammation or swelling of the skin
depression or coma
changes in drinking, weeing and eating
What to do if you suspect poisoning
Signs of poisoning tend to appear suddenly, so it is important to be aware. Even if you only suspect that your cat has swallowed or touched something poisonous, you must act quickly. Contact your vet immediately. Don't wait for signs of illness as by then your cat may be too sick to survive.
If you can see the poison, take your cat away from it immediately. If possible, take a sample of the poison with you to your vet appointment to help the vet choose a course of treatment.
Your vet may ask you to bring your cat in immediately or may give advice over the phone. Forcing or encouraging your cat to vomit may not be helpful and you should not try to treat your cat’s symptoms yourself.
Human Foods – Poisoning Prevention Tips
Use childproof locks on cabinets and drawers that could contain toxic substances.
Ensure your rubbish cans have secure lids that cats can't open.
Store food, including leftovers and human foods, in secure containers and out of reach of your cat.
Use cat-safe toys by ensuring your cat's toys are non-toxic and free of small parts that could be swallowed
Regularly change water, ensuring your cat has access to clean, fresh water and change it regularly to prevent contamination.