Five foods you should never feed your cat, according to an expert

woman holding treats above cats
(Image credit: Getty Images)

Working out which foods you can and can’t feed your cat can be a minefield. While you don’t need to feed your kitty any ‘human’ food – they can get all of the nutrients they need from some tasty cat food (and maybe some of the best cat treats too!)  – they are allowed some of the foods we eat. 

It’s fairly common knowledge that cats can enjoy much of the same cooked meat and fish as humans, but cooked eggs and many fruits and vegetables are also suitable for cats, even if not all of them like to get their five-a-day! Is tuna good for cats, for example? Can cats eat chocolate?

However, some foods are toxic for cats, and some of them are ones we might not expect. Fortunately, to help us avoid our kitties having upset stomachs at best or serious health issues at worst, Maria Kozlova, a certified cat trainer and behaviorist and founder of Cats Explained, explained some of the main foods to avoid in an Instagram post. 

So, what human food can cats eat, and what’s out of bounds? The first foods Kozlova highlights are garlic and onion. “Garlic contains thiosulfate, which is toxic to cats and can cause a condition called hemolytic anemia, damaging their red blood cells,” she says. 

Likewise, onions contain thiosulfate too, and even in small quantities eating onion can cause hemolytic anemia. Avocado is another food that cats shouldn’t eat, with Kozlova explaining that it contains the fungicidal toxin persin. This can cause vomiting and diarrhea in cats, so it’s best avoided.

Chocolate is another food that’s poisonous for cats. While many pet parents know this already, it’s worth reiterating just how serious chocolate can be. As Kozlova explains, “Theobromine, an ingredient found in chocolate, is highly toxic to cats, causing symptoms like restlessness, rapid breathing, muscle tremors, and potentially fatal heart arrhythmia.”

And, finally, Kozlova mentions grapes. “The exact toxin in grapes is unknown,” she says, “But consumption can cause acute kidney failure in cats, making them highly dangerous.” 

This isn’t an exhaustive list – there are lots of other things that aren’t good for cats to eat. Some are more obvious, like alcohol and coffee, while others, like nuts, are perhaps more surprising.

If you’re unsure, it tends to be best to err on the side of caution. After all, most cats get everything they need from their cat food. And as Kozlova says, “If you notice any signs of sickness, contact your local vet.”

Thinking of trying to improve what your cat eats? You might find this article useful: 5 ways to improve your cat’s diet

Adam England
Freelance Writer

Adam is a freelance journalist covering pets, lifestyle, health and culture, and he has six years' experience in journalism. He was senior editor at DogTime.com, and has written for The Independent, GoodToKnow and Healthline

He's also spent the last few years studying towards undergraduate and postgraduate degrees in journalism. While a cat person at heart, he's often visiting his parents' golden retriever, and when he's not writing about everything pets he's probably drinking coffee, visiting a cat cafe, or listening to live music.