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Food & Diet

Can My Dog Eat Onions?

At A Glance

While some vegetables are beneficial to dogs, others may not be.

In this article, we will understand if onions are good for dogs or not.

Last Updated on: Feb 28, 2022

Can my dog eat onions? This question is common among pet owners concerned about their dog’s health.

Having been part of the human diet for thousands of years, the onion is a diverse, delicious vegetable that’s used in cuisines around the world. It’s not the same for our furry friends though, as many foods that we consider tasty might be harmful to dogs!

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Can My Dog Eat Onions?

No. Your dog shouldn’t eat onions.

Keep in mind that all parts of onion including the leaves are poisonous to dogs, as they contain disulfides, which dogs cannot digest. This includes vegetables that belong to the allium family, for instance, garlic and leek.

If you’re wondering about the amount of onion that could make your dog sick, it’s worth noting that it doesn’t take a lot for serious health issues to arise in dogs.

Just like chocolates, consuming even small quantities of onions can make dogs sick. Generally, toxicity arises when a dog ingests over 0.5% of its body weight at one sitting – for most dogs, this should be about a quarter-pound of onion.

Remember, the smaller your dog, the greater the risk. While the consumption of a small onion might not be harmful to a 150-pound mastiff, it could cause severe health symptoms in a 10-pound dog such as a Chihuahua.

Can My Dog Eat Cooked Onions?

It doesn’t matter whether you give your dog a cooked or raw onion. It only takes a few onions to cause poisoning.

Ensure any broth you feed your dogs doesn’t contain onions.

Cooking onions doesn’t eliminate the chemical, so it’s just as hazardous for your dog.

How Toxic Are Onions For Dogs?

Onions contain a toxic compound called N-propyl disulfide. The compound breaks down red blood cells, causing anemia in dogs.

The toxin also yields oxidative damage to your pet’s red blood cells by linking together the oxygen molecules in your pet’s red blood cells. This decreases the capacity of the red blood cells to transport oxygen and tricks a dog’s immune system into attacking its own red blood cells.

The red blood cells face destruction in a process termed hemolysis, leading to hemolytic anemia. This means that the destruction of the red blood cells will occur faster than the production; without treatment, this can potentially result in death.

Why Can Humans Eat Onions Without A Problem?

The digestive system of animals evolved differently from humans. In the case of onions, it all comes down to the differences in our red blood cells.

Unlike human RBCs, dogs have more ‘areas’ on their cells where oxygen can link up. While this helps keep them energetic, it also makes them susceptible to disulfide compounds, which barely affect us.

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Signs of Onion Poisoning in Dogs

Symptoms can differ based on the number of onions consumed by your dog, the size, and the rate at which onion consumption took place.

This means that a small breed consuming numerous onions very fast will exhibit more severe symptoms than a huge dog consuming a small number of onions at a slower pace.

What are the symptoms of a dog eating onions? Here are the most common ones:

  • Pale gums
  • Fainting
  • Decreased appetite
  • Reddish urine


If you notice any of these signs, consult a vet. Although diarrhea and vomiting might occur within a day, it might take numerous days to one week after your dog consumes onions for anemia symptoms to emerge.

The faster you get your pet to the vet, the better his chances are for recovery. You could also prevent recurring poisoning in the future by keeping onions out of your pet’s reach.

As your dog’s condition progresses, the regeneration of new red blood cells will take place and anemia will pass as long as you avoid further exposure. High doses however might need treatment through a blood transfusion to prevent fatally low erythrocyte levels.

What to Do if Your Dog Eats Onions?

While activated charcoal and other quick fixes can help, it’s best to not take any chances and rush to your vet.

You’d rather be on the safe side by contacting a vet who will be better placed to catch the symptoms and treat them accordingly.

Possible solutions include performing stomach flushing, gastric lavage, or inducing vomit.

In case of a skin issue, bathing with prescribed medication might be necessary.

Ensure you seek treatment as soon as possible to avoid damage to your dog’s red blood cells. Always have an emergency contact in handy in case your vet isn’t available. If the condition is severe, your dog might need to spend considerable time in the hospital.

Can a Dog Recover From Eating Onions?

Dogs recover from mild onion exposure, however; severe poisoning can be lethal, particularly without treatment.

If you’ve established that your dog has consumed an excess quantity of onions, you must take him to a vet even if immediate signs aren’t evident.

The best means to manage the issue is by avoiding exposure in the first place. If you feed your dog on food meant for humans, examine the ingredient list for garlic, onions, or other allium products.

Even if your dog is asymptomatic, constant low-level doses will worsen any accidental ingestion. You want to dispose of any spoiled food that comprises onion products in a garbage disposal or a sealed trash can.

dog siting in the kitchen
While onions are a culinary favorite for most people, they can be fatal for dogs. You want to avoid feeding your dog the vegetable to avoid serious complications.

It’s equally important that you seek medical attention fast to improve your dog’s chances of recovery. Thankfully, now you know exactly how onions can affect a dog’s health, and how seriously to take the issue if it does arise.


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Meet Paul, a devoted dog dad to the delightful French Bulldog, Cofi. With a flair for humor and a deep understanding of Frenchie quirks, Paul brings a lighthearted touch to his writings. His relatable stories and practical insights are a blend of laughter and valuable advice and resonate with fellow dog owners.

Through his words, Paul aims to celebrate the joys and challenges of being a dedicated pet parent, reminding you that life is simply better with a four-legged, snorting sidekick by your side.