Are Onions Bad For Dogs? – Explained

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There is no doubt that dogs are one of the most popular pets, and great care needs to be taken when it comes to their nutritional diet.

Onions are commonly used to add flavour to foods for enhanced aroma and taste. The question that many dog owners have is: are onions bad for dogs?

In this article, we’re going to fully explore the answer to this question.

Can dogs eat onions?

No, they can’t. No dog of any breed should be allowed feed on any form of onion (or garlic) whether raw, cooked or powdered.

Be warned: even when buying snacks from the store, you need to be very careful with the ingredients used in their preparation. Garlic and onion content can pose serious health risks to dogs and may even lead to death.

Why aren’t they safe for dogs?

Onions aren’t safe for dogs because they contain a compound called n-propyl disulfide.

This substance is generally agreed to be dangerous to dogs because it leads to damage to red blood cells, thus preventing the circulation of oxygen in the body. Oxygen shortage in dogs leads to hemolytic anemia.

Blood circulation is the ultimate engine for the performance of various body functions, and thus when dogs lose circulation, they become inactive. If this persists, dead eventually results.

How much onion does it take to poison a dog?

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It is also worth understanding the amount of onion needed to poison a dog. According to various research done by dog specialists, it has been found that the toxicity threshold depends on the dog’s weight.

In general, it takes 100 grams of onion per 20 kg of body weight to see effects of toxicity. For those that don’t know what this looks like, it’s about one small to medium-sized onion. But that doesn’t mean that a smaller piece wouldn’t be dangerous.

You should also note that onion (and garlic) powders are more dangerous to the dogs than actual onions. Care should also be taken with cats – onions are even more toxic to cats than they are to dogs.

What about cooked onions?

Dogs shouldn’t be fed cooked onions either, as they still contain the toxic compound.

This explains the reason why it is generally unsafe to feed dogs human foods or scraps from restaurants, cafes or hotels. Chances are good that many of these products are prepared using onion or garlic products.

As a dog owner, you have to watch this and feed your dog proper dog food as much as possible. This is beneficial because dog food contains all the nutrients necessary for the growth and development of the dog as well as enhancing the overall dog’s health.

Symptoms Of Onion Poisoning

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You know by now that dogs must not eat green onions, cooked onions, or powdered onions. But it’s not possible to babysit your dog 24/7, and sometimes they’ll eat something without your knowledge or permission.

Whether you’re at work, running errands, or have somewhere else to be, you should know the signs and symptoms to look out for so that if your dog does eat something dangerous, you can take fast action.

The following are some of the signs of onion toxicity than can be linked to hemolytic anemia:

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

If your dog exhibits these symptoms, seek medical care and treatment immediately by calling your local vet clinic.


A wise man once said: prevention is better than treatment. It’s the least costly way to go, and hence you should try as much as possible to prevent your dog from coming into contact with onions.

But in case it happens and your dog is showing some of the above symptoms, call your vet clinic right away and fill them in on the situation.

A qualified veterinarian will diagnose your dog and determine the best course of action; this might be induced vomiting where the dog will be able to expel the ingested onion.

The veterinarian will also put your dog on proper supportive care that will help to replenish the destroyed red blood cells. This way, your dog will not be exposed to the risk of hemolytic anemia.

Similar Foods That Are Toxic To Dogs

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Onions certainly aren’t the only food that are harmful to dogs. Garlic is also toxic to dogs, as is alcohol in raw dough, avocado, chocolate, caffeine, certain mushrooms, tomatoes, grapes and resins, and sugar-free foods.

Before feeding your dog anything that humans eat, do your research to ensure that there’s no risk.

Similar Foods That Are Safe For Dogs

Some human foods can be fed to dogs safely, cooked or raw, without any adverse health effects. These include certain mushrooms, cooked potatoes, green beans, cooked rice, boiled chicken, broccoli, cooked pumpkin, and bell peppers.

Nevertheless, it is important to note that new foods should be introduced to dogs gradually and with care to prevent your dog from overreacting to the food.


Are onions bad for dogs? As discussed above, the answer is yes. This is due to a compound that is disastrous to dogs’ health.

Onion and garlic products should be kept away from a dog’s diet. However, this doesn’t mean that your dog can’t eat other vegetables or fruits. For starters, you can check out our articles on strawberries and mushrooms.

Thanks for reading this article. If you have any questions, feedback, or want to share your experience with dogs and onions, feel free to leave a comment.

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