Can Dogs Eat Onions?
No. Onions are toxic to dogs in every form (raw, fried, roasted, dried, powdered or in broth) because they damage red blood cells and can cause hemolytic anemia.
Why it's dangerous
Onions and the rest of the Allium family contain sulfur compounds (thiosulfates and disulfides, especially n-propyl disulfide) that dogs can't metabolize well. They oxidize hemoglobin, form what are called Heinz bodies and make red blood cells break down early: the result is hemolytic anemia. Cooking doesn't help, because these compounds survive heat, and onion powder or dried onion is even more concentrated.
Effects have been reported from about 5 g per kg of body weight (around 0.5% of the dog's weight): roughly 50 g (under 2 oz) for a 10 kg (22 lb) dog, a third of a medium onion. The effect is also cumulative, so small amounts repeated over several days (leftover stew, gravy, meatloaf, pizza, baby food or store-bought broth) can also end in anemia. Symptoms usually take 1 to 5 days to appear, and Japanese breeds such as the Akita and the Shiba Inu are more sensitive.
Is any amount safe?
There's no safe or recommended amount for any size of dog. A single small piece rarely causes problems in a large dog, but the damage adds up with every exposure, and onions offer nothing that safe vegetables like carrots or zucchini don't.
Risks
- Hemolytic anemia from the destruction of red blood cells
- Cumulative effect: daily leftovers cooked with onion add up
- Concentrated forms: onion powder, dried onion, soup mixes and bouillon cubes
- Prepared food: meatloaf, burgers, gravy, sauces, stuffing, pizza, baby food
Frequently asked questions
What happens if my dog eats a little cooked onion?
If it was a small piece and your dog is medium or large, most likely nothing will happen, but call your vet to confirm based on their weight and the amount. Cooked onion is just as toxic as raw onion and the damage builds up, so don't let leftovers from stews and casseroles become a habit.
How much onion is toxic to a dog?
Effects have been reported from about 5 g per kg of body weight, around 0.5% of the dog's weight: roughly 50 g for a 10 kg (22 lb) dog, a third of a medium onion. The effect is also cumulative, so small repeated amounts add up, and onion powder is far more concentrated. That's why there's no amount we can call safe.
Can my dog have chicken broth with onion?
No. The toxic compounds in onion pass into the broth even if you remove the pieces, and store-bought broth and bouillon cubes usually contain onion powder and a lot of salt. If you want to give your dog broth, make it at home with just water, meat and safe vegetables like carrots or zucchini, with no salt.
General information reviewed against veterinary sources. If your dog has eaten something that worries you, call your vet or a 24-hour emergency vet right away, without waiting for symptoms.