Vegetables · updated 2026-09-12
Can dogs eat onions?
No. Onions damage dogs' red blood cells.
Why
All alliums — onion, garlic, leek, chive, shallot, spring onion — contain thiosulphates that destroy red blood cells and cause haemolytic anaemia. Raw, cooked, powdered and dried forms all count; onion powder in gravies, stocks, baby food and takeaways is a common hidden source.
What to do instead
Never. Check ingredient lists on anything savoury you share.
Symptoms to watch for
Symptoms can take days: weakness, pale gums, fast breathing, dark or reddish urine, vomiting. Call your vet if any amount was eaten.
If your dog has eaten onions, don't wait for symptoms.
Call your vet, or in the US the ASPCA Animal Poison Control Center (888-426-4435) or Pet Poison Helpline (855-764-7661), 24 hours a day. Have the amount, the time and any packaging ready.
And for cats?
Toxic. No. Cats are even more sensitive than dogs. Can cats eat onions? →
Related foods for dogs
See the whole list: Can dogs eat…? · printable fridge chart
This guide is general information for healthy adult dogs, based on published veterinary guidance (ASPCA, Pet Poison Helpline, AKC, VCA). It is not a substitute for advice from your own vet, who knows your dog's weight, age and medical history. If you are unsure, ask them before sharing any human food.