Can Dogs Eat Onions? | PUPPYFAQS

Can Dogs Eat Onions?

can dogs eat onions

We add onions to so many human dishes to boost the flavors that it can be difficult to imagine that onions might be harmful to our family pets. 

If you regularly offer servings of your onion-rich home-cooked food to the dog, you may find yourself wondering – can dogs eat onions? 

In this article, we will explore the toxicity of onions and find out whether we should avoid feeding onions to our pets.

not safe for dogs to eat

No, your dog should not eat onions. 

Onions are toxic to dogs. Onion toxicity depends on how much your dog consumes and can lead to a condition called hemolytic anemia. Onion belongs to the Allium family.

In this article, we will discuss:

  • Are onions toxic to dogs?
  • What parts and kinds of onions are toxic to dogs?
  • How much onion is considered toxic to a dog?
  • Symptoms of onion toxicity in dogs
  • Treating onion toxicity in dogs
  • How to prevent dogs from eating onions
are onions safe for dogs?

Are Onions Toxic To Dogs?

The definitive answer to this question is yes, onions are considered toxic food when it comes to feeding our dogs, and we should be avoiding offering any foods that contain any onion. 

This can be easier said than done, as we shall discuss further on in the article.

The N-propyl disulfide compound in onions leads to anemia in dogs as it causes oxidative damage to the red blood cells by attaching to oxygen molecules in the blood. 

This means that the red blood cells are not able to carry the oxygen. 

Related Post: Can dogs eat mushrooms?

This toxic compound also fools the body into thinking that the blood cell is an invader, and this leads to a process called hemolysis in which the red blood cells are destroyed. This is what leads to anemia. 

Onions also contain a substance called thiosulfate, and dogs don’t have the enzyme required to digest this. Onions contain another compound called organosulfur. 

This can lead to a condition called toxicosis, which is brought about by poisoning and can be easily absorbed into the dog’s digestive tract.

Some of the leading health risks of a dog consuming onions are:

  • Liver damage
  • Asthmatic attacks
  • Allergic reactions
  • Anaemia, dermatitis
  • Diarrhea & vomiting
should dogs eat onions

What Parts & Kinds Of Onions Are Toxic To Dogs?

All parts of the onion are toxic to dogs. This includes the flesh of the onion and any juice that comes from it, and even processed onion powders. 

The onions are toxic both raw and cooked, whether you are frying the actual onions themselves or cooking with a powdered variety to add flavor to other ingredients in a dish.

The whole of the allium family should be considered harmful to dogs and avoided. These include garlic, chives, leeks, and shallots.

Perhaps the most important one to consider is onion powder, as this is hidden in so many different types of human food that you may not even be aware of — for example, baby foods and soups.

How Much Onion Is Considered Toxic To A Dog

Toxic effects can be seen in just 100g of onion per 20kg of a dog’s weight. This is about one medium-sized onion. 

You might think as that sounds like quite a lot of onion and that your dog wouldn’t have access to eating such a large amount. 

Don’t forget that onion is hidden in a lot of food and most often used in larger quantities in the form of onion powder, particularly onion and garlic powder, which are even more potent than fresh onions or garlic due to it being so concentrated.

Be aware also that it would be straightforward for your dog to devour an onion casserole if they are accidentally left alone with one, or a plate of onion rings, which could easily add up to toxic quantities of onion for your dog.

Beware also if you have cats in your household because onions are even more toxic to them than they are to dogs.

should dogs eat onions

Symptoms Of Onion Toxicity In Dogs

If your dog has been eating onions, you can lookout for the following symptoms of anemia.

  • Weakness
  • Lethargy
  • Decreased appetite
  • Fainting
  • Pale gums
  • Reddish urine
  • Vomiting
  • Elevated heart rate
  • Panting

The best thing to do if you know your dog has consumed a toxic food like onions are to look out for these signs and take your dog to a veterinarian who will be able to test for anemia using blood work, provide a diagnosis, and treat your dog.

See Also: Can dogs eat infographic

Treating Onion Toxicity In Dogs

It is important to remember that onion toxicity can be fatal for dogs. 

For this reason, if you know that your dog has eaten a large number of onions, you shouldn’t hesitate to take them to see a vet, even if your dog is not yet displaying any symptoms of onion toxicity.

If you take your dog to the vet straight after your dog has consumed the onions, they may decide to induce vomiting to bring back up most of the offending food. 

They may also use activated charcoal to absorb any of the remaining toxic compounds in your dog’s system. Activated charcoal can also be used if your dog has an allergic reaction. 

Supportive care may also be given until your dog’s body can produce a healthy supply of red blood cells to replace the damaged ones. If your dog’s case is severe, they may even need to have a blood transfusion.

are onions safe for dogs to eat

How To Prevent Dogs From Eating Onions

Because onion, in its many forms, is hidden in so many human foods, it can be impossible to keep track of whether your dog is consuming them regularly unless you have strict control over their diet.

This means enforcing house practices so that the whole family understands that the dog must eat dog food and dog treats and not human food, titbits, or table scraps. 

It is even more important to establish strict house rules if you have children in the house because kids are more likely to unknowingly offer the dog foods that may not be good for him.

To help your family keep to the rules, you can make sure that all treats given to the dog are taken out of a special treat jar or a container from the fridge if you want to offer your dog certain human foods like plain chicken or veggies as treats. 

These containers should always be clearly labeled. This will also help you to keep track of the quantities of treats your dog is being fed throughout the week to have better control over their weight.

If you have a habit of offering titbits to your dog, there are particular foods to be careful about offering. 

For example, pizza leftovers are never a good idea, as toppings and sauces may contain onions or onion powders and other ingredients or spices that are not healthy for a dog, including the bread base and cheese! 

Steer clear of crisps and crackers that may be heavily seasoned with salt and onion powder, or other flavorings that are detrimental to your dog’s health. 

Home cooking, while it may be super healthy and wholesome for you and your family, could be harmful to your dog. 

It would be best if you only opted to offer wholefoods that are protein-based and that have not been processed or cooked with sauces and spices.

Please keep your dog away from onions and other toxic human foods by offering them a healthy and balanced diet that is designed specifically for them, and not for people. 

Some great new dog food companies are popping up now that offer home subscription services to “home-cooked” dog food that uses human-grade ingredients that are safe and nutritious for your dog. 

The great thing about these kinds of subscriptions is that you often get individual meal portions that are perfect for your dog, which can go a long way in helping to keep your dog at a healthy weight. 

The best thing is that they taste great to your dog without needing onions or garlic to boost the flavors like in many human pre-prepared meals.

Don’t forget that you should be especially careful with the types of human food you give your dog when you have a small-sized dog as it takes far less of the food to have a toxic effect on your dog.

Related Post: Can dogs eat Pepperoni?


It is easy to make mistakes with our dogs’ health when we assume that they are just like us. 

The fact is that there are so many human foods that can harm our dogs’ health. Many human foods are not even healthy for us, never mind our dogs. 

Keeping informed by reading articles like this one can help to keep your dog safe, and that means fewer expensive trips to the vet and less stress for the family. 

can dogs eat onions?


I'm a self-employed blogger, life-long pet parent, and lover of dogs. I have always loved animals, especially puppies. So when my family got our first dog 15 years ago, it was love at first sight. We named her Sassy because she was so small, cute, and had a sassy personality! Once we got her home, I wanted to know everything about caring for her, so I researched online. Eventually, this led me to create the PUPPYFAQS website, where I write about nutrition, health, and care of puppies and the latest news in the world of puppies. In my spare time, I volunteer at my local shelter, which is run by volunteers who are passionate about helping homeless dogs find their forever homes. If I'm not working or volunteering for dogs, you can find me spending time with my family, friends, and my puppy. I have been writing professionally online since 2009. In addition to PUPPYFAQS, I also write for several other pet-related publications.

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