Can Dogs Eat Onions? Absolutely Not!

Can a dog eat onions?

The answer is a definite – NO! Onions, along with garlic, scallions, and leeks, are toxic for canines!

What happens if your pup has eaten onions?

Read on for the most critical information regarding onion poisoning, including the symptoms, diagnosis, prognosis, and treatment.

More about the onions

Onions are a favorite vegetable and the main ingredient for many dishes. Other members of this allium family include leeks, garlic, shallots, scallions, and chives, all of which are ingredients that we tend to use daily when cooking.

However, these root vegetables can cause canines mild to severe and life-threatening toxicosis.

It doesn’t matter whether the onions are yellow, white, or green or whether they are cooked or not. Nor does it matter whether the dog eats the flesh or the skin, leaves, or juice of the onion. All of these can pose a real danger for the pup.

Some breeds, such as the Japanese dog breeds Akita and Shiba Inu, are the most susceptible to onion poisoning, according to the ASPCA.

What happens to a dog that eats onions?


The reason for the high toxicity of onions for dogs is the n-propyl disulfide contained in them. This organic compound causes damage to the dog’s red blood cells. This can lead to hemolytic anemia.

The n-propyl disulfide is found in all parts of the plants from the allium family. It is a sulfur-based compound, and dogs lack enzymes to digest it. It is also toxic for the dog once it enters its organism.

This compound gets attached to the red blood cells, especially the hemoglobin in the bloodstream. Hemoglobin is the protein that carries oxygen to all organs and parts of the dog’s body.

As n-propyl disulfide attaches itself to hemoglobin, it begins to cause oxidative damage to the red blood cells. This inhibits them from carrying oxygen normally. Instead, the damaged blood cells clump together in Heinz’s body. These clumps can be seen under a microscope as purple blobs on the cells and are telltale signs of onion poisoning.

As a result, the dog’s immune system starts fighting these Heinz bodies, regarding them as foreign invaders. So, the body begins destroying its own red blood cells, a process which is known in scientific terms as hemolysis.

When left without treatment, this process will continue, and the body will continue destroying the red blood cells much faster than new ones are produced. Plus, the new blood cells that are made have shorter lifespans than the healthy ones.

As a result, the organs and body of the dog cannot receive the oxygen it needs to function properly. All of this results in a severe state of anemia.

The symptoms of onion poisoning can appear immediately but often occur 2-3 days after the dog has ingested the onions.

  • Some of the most common symptoms of onion toxicity include:
  • Abdominal upset and pain
  • Lethargy
  • Low stamina and sometimes fainting while or after exercise
  • Pale gums
  • A loss of appetite
  • High heart rate or increased respiratory rate
  • Vomiting
  • Diarrhea
  • Ataxia – Loss of coordination
  • Discolored urine
  • When left untreated, this can lead to kidney failure and death.

Is there a safe amount of onions that I can give to my dog?

No! There is no safe amount of onions or any other allium family plants, which is safe for canines.

It only takes onions that weigh 0.05% of the dog’s weight to become toxic to the pup. This means that a small onion can poison a 45-pound dog. Imagine what it can do to a toy dog like a Yorkshire terrier!

One of the most frightening things about the hemolytic anemia resulting from onion consumption is that it can slowly build up in your dog’s bloodstream. It can take a long time too.

This means that even if your pup nibbles just a tiny bit of onion that falls out of your burger or pizza or eats food that has been cooked with onion, this can start building up in its system. As a result, the symptoms of this onion poisoning will become evident.

Please note that onion and garlic powders are much more concentrated than the plants themselves and, as such, are even more toxic for dogs. So, avoid giving your dog even the tiniest amount of these powders!

What is the treatment for onion poisoning in dogs?

If you suspect your pup has eaten onions or just a part of an onion, contact your vet immediately. The faster you act – the better the chances that the dog will get treatment and recover!

The diagnosis

Your vet will perform different tests, usually a urinalysis, to check for increased hemoglobin in the dog’s urine. Bloodwork will be done searching for the Heinz bodies clusters on the red blood cells.

If you are worried about onion poisoning in your dog, you can call the Animal Poison Control Helpline.

The treatment

If the onions were consumed recently, your vet would probably try inducing vomiting, or a stomach flush may be performed to remove the undigested bits of onion.

Also, activated charcoal will probably be administered to absorb as much of the toxins as possible from the gut.

Your dog may be given IV fluids so that the bloodstream is flushed of the toxins and so that the pup remains hydrated.

The dog may require blood transfusions and supplemental oxygen in more severe cases.

The prognosis

Your pup will likely need to remain in the clinic for close observation until the poisoning crisis is averted.

Most dogs recover completely and relatively quickly in mild cases of onion poisoning. More severe cases may require more recovery time.

In cases like this, having pet insurance can be really helpful. It will allow you to focus on your fur baby’s health and life instead of worrying about the costs of veterinary care.

One thing to note is that cats are even more prone to onion toxicity than dogs.

In fact, a few years ago, veterinarians noted a spike in cases of onion poisoning among felines. It turned out that the reason was baby food which contained onion powder which was used for enticing the appetite of cats. Thankfully, today’s baby food does not contain onion powder.

Final verdict about onions and dogs

Any type of onion and any part of it can be toxic and dangerous for your dog! It doesn’t matter whether the onion is cooked, raw, or is used as an ingredient for a meal you have prepared. So, avoid giving your pup any food that contains onions, not even a tiny bit.

Onion toxicity can build up in the dog’s body over time, leading to mild or severe symptoms, anemia, and even death!

Due to its strong toxicity, you should never give onions to your pup because there is no safe amount for them.

While larger dogs can maybe handle eating a small onion without repercussions, even a small amount of onion can be fatal for a toy-sized or small dog.

So, even if you adore onions, garlic, scallions, leeks, shallots, or onion and garlic powder, never share them or any foods made with them with your pup!

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