Dogs · Guide
Can Dogs Eat Onions?
No, onions are toxic to dogs in every form. They can damage red blood cells and cause anemia. Learn the signs, which forms are risky, and what to do.
No, dogs should not eat onions. Raw, cooked, fried, or powdered, onions can damage a dog’s red blood cells and lead to anemia, which means the body has too few healthy red blood cells. A small piece may not hurt a big dog, but there is no safe amount to count on. Call your vet if your dog eats any.
Why are onions bad for dogs?
Onions belong to the Allium family, along with garlic, chives, and leeks. The Merck Veterinary Manual says sulfur-containing compounds in these plants are thought to cause red blood cells to break apart. The ASPCA names one of them, N-propyl disulfide. When too many red blood cells break down, the dog becomes anemic and weak.
The risk is not limited to fresh onion. Merck lists raw, cooked, dried, and powdered onion as risks. The AKC adds that onion and garlic powders are even stronger than fresh onion.
How much onion is too much?
Merck says dogs have gotten sick after eating 15 to 30 grams of raw onion for every kilogram of their weight. The AKC gives a similar warning: about 100 grams of onion (roughly one medium onion) for every 20 kilograms of dog. That is about 45 pounds.
Those numbers are not a safe limit. Dogs differ, and Pet Poison Helpline says the amount, the dog’s size, and other factors all matter. Japanese breeds such as Akitas and Shiba Inus are more sensitive. When in doubt, call a vet.
What are the signs of onion poisoning?
Pet Poison Helpline says the first signs are often an upset stomach: nausea, vomiting, and diarrhea. These can show up within a day. Signs of anemia can take several days, up to a week, to appear. Merck says damage to red blood cells often shows up about 3 to 5 days after eating.
Watch for:
- Weakness or being very tired
- Pale gums
- Not wanting to eat
- Red or dark urine
- Fast heartbeat or panting
- Fainting or collapse
What should I do if my dog ate onion?
- Call your vet or a poison hotline right away. Don’t wait for signs.
- Share the type of onion, how much, when, and your dog’s weight.
- Follow their advice. The vet may make your dog vomit, give fluids and other care, or in severe cases use a blood transfusion, according to the AKC and Merck.
Other kinds of onion
Can dogs eat red onion?
No. Red onion is an onion, so it carries the same risk as yellow or white onion. The ASPCA and Pet Poison Helpline do not list any onion color as safe.
Can dogs eat cooked onion?
No. Cooking does not remove the danger. Merck and the AKC both say cooked and fried onion can still poison dogs.
Can dogs eat onion powder or onion soup mix?
No. These are more concentrated. Merck names dried flakes, powders, and dry onion soup mixes as risks. Check labels on seasonings, gravies, and sauces, which often include onion or garlic.
Can dogs eat chicken broth with onions?
No, not if it has onion in it. Onion cooked into broth is still onion. None of our sources set a safe amount, so skip it. If your dog drank some, call your vet. Always read the broth label for onion and garlic.
Can dogs eat onions and tomatoes?
No, because of the onions. Tomatoes by themselves are a different story. The ASPCA says ripe tomato fruit is non-toxic, while tomato plants and unripe green tomatoes are toxic. So a dish with both, like salsa or pasta sauce, is still a problem if it has onion.
Can dogs eat onions safely?
We found no way to feed onion safely. No source we read gives a safe amount, a safe cooking method, or a safe form. The safest choice is to leave it out of your dog’s food.
What can my dog eat instead?
Choose treats made for dogs, and keep all treats to about 10% of your dog’s daily calories. Check labels for onion and garlic on anything made for people. For more foods to avoid, see our guide to foods that are toxic to dogs.
Common questions
How much onion is toxic to a dog?
The Merck Veterinary Manual says dogs have shown signs after eating 15 to 30 grams of raw onion per kilogram of body weight. That is a lot, but sizes and sensitivity vary, so call a vet after any onion.
How long after eating onion will a dog get sick?
Upset stomach can start within a day. Signs of anemia can take several days to appear, so a dog that looks fine at first can still get sick later.
Are some dogs more at risk from onions?
Pet Poison Helpline says Japanese breeds, such as Akitas and Shiba Inus, are more sensitive to onions and their relatives.
Can dogs eat garlic, chives, or leeks?
No. Pet Poison Helpline says onion, garlic, chives, and leeks are all in the same plant family and are all poisonous to dogs. Merck says garlic is about 3 to 5 times more toxic than onion.