Food safety

Can Cats Eat Onion?

Toxic — call your vet now — Onion for cats.

Toxic — call your vet now

Why: Onions contain thiosulphates that damage a cat's red blood cells and cause anaemia. All forms are toxic — raw, cooked, powdered or dried — and the damage can build up over several small exposures, so onion powder in sauces and baby food counts too.

If your cat ate onion: Call your veterinarian or ASPCA Animal Poison Control at (888) 426-4435. Note how much was eaten and in what form. Pale gums, weakness, rapid breathing, vomiting or dark urine need veterinary care the same day.

Related: Garlic, BBQ Sauce, Sausage, Bologna

Why this verdict

Onions contain thiosulphates that damage a cat's red blood cells and cause anaemia. All forms are toxic — raw, cooked, powdered or dried — and the damage can build up over several small exposures, so onion powder in sauces and baby food counts too.

If your cat ate onion

Call your veterinarian or ASPCA Animal Poison Control at (888) 426-4435. Note how much was eaten and in what form. Pale gums, weakness, rapid breathing, vomiting or dark urine need veterinary care the same day.

Related foods

Garlic, BBQ Sauce, Sausage, Bologna

Check another food

Back to the Food-Safety Checker to check all 90 foods, or see the beginner feeding guide and the feeding estimator.

Before you use the result

Use the result as a starting point for observation and planning. Cats vary by age, body condition, temperament, medical history, and household setup.

Sources: ASPCA Animal Poison Control — People Foods to Avoid Feeding Your Pets, the ASPCA Animal Poison Control Center, and the Cornell Feline Health Center — Feeding Your Cat. Chocolate toxicity figures are approximate values from the Merck Veterinary Manual. If your cat ate something on the toxic list, call your veterinarian or ASPCA Animal Poison Control at (888) 426-4435.