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Can Cats Eat Onions?

No, avoid

Do not give onions to cats.

Emergency? Call your vet or an animal poison hotline straight away: ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661 (US numbers, a consultation fee may apply).
Illustration of onions

Are onions safe for cats?

Onions belong to the allium family with garlic, chives, leeks and shallots, and are used in a huge range of cooked dishes. Onions in any form are toxic to cats, who are even more sensitive than dogs. They damage red blood cells and can cause anemia.

What to do instead

What to avoid

How many onions can my cat have?

There is no amount of onions that we can recommend for cats. Skip them entirely.

Signs your cat may be having a problem

Watch for vomiting, diarrhea, drooling, pawing at the mouth, loss of appetite, tiredness, a swollen or painful belly, or trouble breathing. Contact your vet right away if you see these signs, or if your cat has eaten any of the parts listed above.

Important: Signs can appear several days after eating onion and may include weakness, pale gums, fast breathing, dark urine, vomiting and loss of appetite. Cats are especially sensitive, so call your vet even after a small amount.

Frequently asked questions

Can kittens eat onions?

No. Onions should not be given to cats of any age.

What should I do if my cat ate onions?

Call your vet or an animal poison hotline right away, even if your cat seems fine. Tell them what was eaten, roughly how much, when, and your cat's weight. Do not try to make your cat vomit unless a vet tells you to.

Is there a safe amount of onions for my cat?

There is no amount of onions that we can recommend, and some cats react to very small amounts. It is best not to give any.

More questions cat owners ask

Wondering about the other pet in your home? Can Dogs Eat Onions?

Last updated September 2026. This page is general information and is not a substitute for advice from your veterinarian. Every cat is different, so check with your vet before adding new foods, especially if your cat has health problems, is pregnant, or is very young or old.