Can Dogs Eat Onions? Here’s What You Need To Know

Can dogs eat onions? And what are your next steps if your dog ate onions? The facts about onions and dogs are a little complicated — let’s find out more.

Dog with toxic foods
Grapes, chocolates, onions, and some other humans foods are toxic to dogs. Photography ©humonia | iStock / Getty Images Plus.

Onions are unique members of the root vegetable family because they (like garlic) are bulbs and do not grow as deeply as other root vegetables. Onions come in white, yellow, and red bulbs, as well as chives and leeks, and are a common flavorful addition to meals and side dishes, served both cooked and raw. They help bring flavor to many of our favorite dishes, but can dogs eat onions? If your dog ate onions, what do you do?

First, what to know about dogs and onions

We spoke with Emmy-award winning veterinarian Dr. Jeff Werber to learn more about how dangerous onions are for our dogs. Dr. Jeff explains, “Traditionally, we have always recommended avoiding raw onions and raw garlic because of a type of toxin that can have a negative effect on red blood cells.” The toxic ingredient is called n-propyl disulfide, which is an oxidant that can do oxidant damage to red blood cells.

Can dogs eat onions?

Well, you shouldn’t give your dog a bowl of onions to snack on. Onions aren’t healthy for dogs, but unlike grapes, where even a small amount can be toxic, onion toxicity depends on how much of an onion a dog consumes. Embrace Pet Insurance Claims Manager Rachel Hinder RVT explains that “Typically if a dog ingests only a small amount of onion, it should not cause any problems.” However, she did caution that “the size of the dog also matters, small pieces of onions are a lot bigger problem for tiny 3-pound Yorkies than 200-pound Great Danes.”

One of the dangers of onions and dogs is that the toxins can build up in their system, meaning that they could slowly be reaching a point where an onion exposure could get them sick, or that there might be what Dr. Werber calls a cumulative effect. “To be safe, avoid onions and garlic,” Dr. Werber suggests. Consuming onions can lead to dogs developing a condition called hemolytic anemia. This condition impacts/destroys a dog’s red blood cells, leaving dogs without enough of them for healthy functioning. Severe onion poisoning in dogs can be fatal.

Can dogs eat cooked onions?

Although onions might not be as toxic to our dogs as grapes or xylitol, avoid giving onions to your dog regardless of if they are raw or cooked. Cooking onions doesn’t have an impact on the safety of onions and cooked onions are still poisonous to dogs because of their toxic effect on a dog’s red blood cells. All forms of onion can be toxic to dogs — whether powdered, dried, fresh or cooked.

Can dogs have broth cooked with onions?

If you are cooking for your dog or treating your dog to some snacks from your plate, avoid sharing any food with your dog that has been cooked with onions including if you use onions in your broth. Hinder advises that “although a small amount of onion is unlikely to cause problems, it is safer to avoid all together.”

Similarly, if you are purchasing a pre-made broth, read the labels on the broth and select a broth that doesn’t include onions. Hinder encourages dog guardians to also look for onion powder as an ingredient in pre-made foods and avoid using in any recipes you will be sharing with your dog because it is made up of dried and ground onions and can be harmful to your dog.

No matter if you are using the onion’s juice, flesh or even leaves, all parts of the onions will cause issues with dogs. Do not cook something with onions for your dog or even onion powder.

What to do if your dog eats onions

To be safe, keep all onions and all products containing onions away from your dogs. But what happens if you’re cooking and you drop a slice of onion on the floor or a friend shares a bite of their lunch with your dog and it includes onion? While we don’t want our dogs eating onions, having a bite of something with onion isn’t likely to make your dog sick. “Your dog probably would not eat enough to cause a real problem because dogs typically don’t like the taste,” Dr. Werber says.

If you think your dog ate onions in large quantities, or if your dog seems like he isn’t feeling well, Dr. Werber suggests seeking immediate veterinary care. Your veterinarian will be able to evaluate your dog and determine if any treatment is necessary.

Symptoms of onion toxicity are symptoms of anemia — when your dog has low red blood cells. Look for decreased appetite, weakness, lethargy and pale gums. The ASPCA’s animal poison control site ( also says that clinical signs include vomiting, panting and high heart rate. If you see any of these symptoms, take your dog immediately to the veterinarian.

Thumbnail: Photography © vvuls | iStock / Getty Images Plus. 

This piece was originally published on May 4, 2018.

Plus, are onions good for YOU? Learn about the health benefits of onions >>

Read more about what human foods dogs can and can’t eat on 

74 thoughts on “Can Dogs Eat Onions? Here’s What You Need To Know”

  1. About how long the symptoms begin. We have an 80lb chocolate lab/pit mix, we know a bag of medium sized onions was opened, but we don’t know if she ate a whole onion or just tore off a peel.

  2. My 1 pound chihuahua puppy ate a small pierce of onion cube. She still eating good and poop is fine . My only concern is that she is not being as playful. Should I be concerned ? She ate the piece about 12 hours ago and has already pooped twice and the poop looks fine.

  3. In Ghana, most often we serve our dogs with a portion of the same meal we eat. For example we prepare chicken soup which of course includes onion, pepper and other spices. Then we prepare corn dough by cooking until it becomes sticky and thick. then when cool, we break it into small pieces and pour some soup on it for the dog. That will be the dogs main food for over many years. Our dogs are healthy and strong. My dog loves indomie. This contains onion.

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  8. Informative article, but just a note: if I’m reading an interview on health by a veterinarian I care about their medical credentials and not that they won an Emmy. While winning an Emmy is impressive it was rather like hearing that my surgeon won an Oscar.

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  17. I don’t give my dog onions or garlic; but, many years ago, in the late 60s and beyond to about the mid to early 80s, I had a dog who came to live with us as a stray. He ate primarily dry and canned dog food; but, once a year, my mom would give him some samplings from our Thanksgiving meal. So, he got a bit of everything, including turkey, sweet potatoes, mashed potatoes, green beans, stuffing, cornbread or rolls, even a bit of pumpkin pie. My dad made the stuffing with chicken broth, chopped up giblets, onions, celery, some kind of nuts, and either cornbread or regular bread. My dog suffered no ill effects from having a little onion once a year.

  18. watchmeuseafakeemail

    it would be nice to have a quantitative measure of how much “toxin” (like disulfide) is toxic a LD 50 number…

    I just got a puppy and fed her some onion withough thinking because I was cooking and though she might like to taste, then tough “oh crap I better google if it’s dangerous” (I should have done it before, and now I’ll try to avoid it) but this article (and most of the info on net/from the vet) is useless use common sense!

    Cats and Dogs evolved around us, and I’m pretty sure people 100 years ago didn’t know what disulfide was or had GPS to know how far a puppy SHOULD walk…

    I’m still great full that somebody took the time to write this article, but I’m sick of hearing people talk like “expert” about cats and dogs teaching bad habits by telling them, everything they do is deadly. BUT this time I messed up 🙂 no onion for her or my 16 year old cats that have eaten so much random food that I never though of researching 🙂

  19. Hi there
    Gave my dog, 50lb lab hound mix, some of our roast beef dinner two nights ago. She has had diahrea and been very sleepy since but no other symptoms you’ve described. What should I do?

  20. Great article, thankyou. Has it always been known throughout history about these toxic foods for dogs? I’m sure when I was younger (a fair while ago) dogs were considered omnivores who could be given any manner of leftovers from the dinner table. Given dogs have been around humans for thousands of years, it just seems a bit odd that its only recently these concerns have been raised about foods that are toxic to them…

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  24. Two days ago I gave my dog one sour cream and onion pringle and the next day he started vomiting liquids then the vomit turned foamy then to liquids and foam. He vomited every few minutes during the day and through the night. so I gave him water and kept him in bed. is there anything I can give to help him feel better?

      1. This doesn’t help at all. My dog ate exactly 4 onion rings and this doesn’t answer if he will be okay. All it does is say how toxic onions are to dogs. Try answering the question specifically so we can all have correct info.

    1. It sounds like your dog had parvo, I hope he made it through it ok, my dog contracted parvo the same exact time, late Nov. early Dec. 2018. I had to give my dog Tamaflu once a day and IV fluids subcutaneously every 2-4 hrs. for one week straight, no sleep but he pulled through, i pray yours did too.

  25. Kathleen Johnson

    We have had dogs live until late teens. They all have eaten what ever I cooked for dinner. They all have eaten cooked yellow onion and cooked raw garlic over the years. I am not advocating to feed your pets these things. But I believe in moderation, it will not hurt most dogs. I am talking that I have had at least ten different dogs eat my spaghetti, meatloaf, beef stew etc. and not had any negative consequences. Our dogs do not eat dog food anymore with all of the problems the various companies that have had problems that kill pets over the years.

    1. I totally agree about getting dogs off ‘dog food’ and onto a homemade diet. It’s horrible to think about what your dog is eating when they are fed ‘food’ that companies deem worthy for dogs. That stuff is much worse than a little bit of cooked onion here and there.

      Also, to the poster, I’m glad you are telling everyone to call the vet when they are experiencing issues that should be looked at. 😉

  26. I have been adding the same organic chicken broth to Marley’s dinner for months now. I just realized today the “seasoned with onions” ingredient. Should I be worried? It just makes his kibble smell so darn good! What did you find out Christi?

  27. My German Shepherd ate some nachos and vomited several hours later. Then later in the middle of the night vomited again along with what looked like someone spilled red pop all over my floor, but smelled like diarrhea ( didnt look like it, but definitely smelt like it) not sure what to do. I am not sure the nachos had onions on them or not, but if they did it was not much. What should I do wait until after vet opens in about 6 hours, or take her to a 24 hour emergency vet.

    1. Hi Wendy,
      We suggest contacting a vet ASAP. You can find info on emergency vets here:
      And here’s info on a dog pooping or vomiting blood — please get medical attention ASAP:

  28. My dog has kidney stones. Can I use a human home remedy to help him? (boil a red onion and drink the broth). I know onions are bad for dogs but will the broth (in small quantities be detrimental?)
    Thank you for your input.

    1. Hi there,

      Thanks for reaching out! Sorry to hear your dog isn’t feeling well. We suggest reaching out to your vet with this question.

    2. Chanca Piedra can be bought at a Health Store. It is a natural herb from India that I took when I had stones. Turns them to dust within two weeks and they are flushed out. I regularly take this for a week every four months in case there are any forming. Amount you take is based on body weight. It has been around for thousands of years,
      I take glucosamine for my arthritis and my Lab can handle same volume

  29. I gave my dog some pieces of chicken with a small amount of soup. The soup contained tiny pieces of onion. Should I be worried? What could be some early warning signs of toxicity?

    1. I purchased some natural worm meds for my dog and the small treats have garlic in them. When I researched I found that garlic in small quantities does not hurt most dogs and can actually be beneficial. I wonder if the ingredients in garlic accumulate over time in a dogs system and can be harmful? From what I have found so far I don’t think that is the case. I avoid using garlic or onions in my homemade soups and other foods that I prepare because I give my dog very small snacks from my meals and sometimes let her drink a small amount of broth or soup. Many canned or prepared foods have some garlic, onions or both in the ingredients. I doubt a very small amount of either would be harmful to my dog but always wonder about that? Do the toxic ingredients of both garlic and onions build up in a dog’s system? If so do they ever go away or is there a natural way to flush them out periodically?

    2. I’ve also heard about garlic being good for fleas too. I can remember putting a bunch of garlic in their food a long time ago and they tasted it in their food and did not like it but ate more than I would ever give them now which is none since I’m educated on this. Why take the chance? Both dogs were okay afterward but acted like they did not feel well for the rest of the day. How horrifying. Again! This happened years ago. Thank goodness they both lived happily years after that episode. Don’t take the chance. It’s not worth the risk.

    3. I would suggest then to give the fleas as much garlic and onion as your heart desires! Just don’t give any to the dog!!

  30. The article specifically states raw onions and garlic. I cook with both of these items, and if I feed any to my dog I try to make sure there is none in her bite. However, the onion could certainly flavor the food, and I’m not sure if this is a concern (similar to the broth question above). Are cooked onions less risky than raw?

    1. The article specifically states that an onion in any shape or form is bad for your dog. Please refer to the article heading “What about Cooked Onion” for further clarifcation. All onion including onion powder, juice, garlic salt, roast, fried, steamed etc. There is no way to give a dog onions that make it safe or ok. The toxin builds up in the dog and dogs cannot eliminate this toxin. Just don’t do it!

      1. Dude it. Ever ways that it accumulates in digs like carcinogens, or that dogs cannot get rid of thiosulfate.

        Urge caution, yes. But Stop being a mindless scare monger.

    1. Hi John — this piece might help:

  31. Broth does contain the same substances that are toxic in large amounts, but the concentration is far lower, so the dog would have to eat insane amounts to get to toxic levels.

    You’d need to make a bathtub of broth for the amounts to reach the same levels as what you’d find in some spicy sausages (and I’ve seen dogs eating those regularly without any ill effect).

    Not allowing a dog access to some broth is roughly on the same level as taking a dog to the vet after eating a small piece of milk chocolate once, or worrying about getting lung cancer from having been in the same room as a smoker once in a lifetime.

    I’m not a vet, but I do have some understanding of food chemistry.

  32. Christi Carter

    Thank you so much for this very important article!
    It does bring up an additional question for me – can my dog have organic bone broth (chicken) that has been “seasoned” with onions? It’s Pacific brand and there are no onion bits … simply broth…. but it’s included in the ingredients list. She loves it & we have added it to her kibble from time to time. Just curious – don’t want to do her any harm.

    1. Hi Christi,

      Thanks for reaching out! Please contact your vet (even a call or email might do the trick) to check.

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