Can Dogs Eat Green Onions? How Dangerous Can Scallions Be?

One of the best ways humans add flavor to their meals is using onions. Green onions, to be specific, add a fantastic taste and depth to dishes. They can be cooked, eaten raw, or used to garnish cuisines. Green onions, also known as scallions, can make a simple meal look and taste great. So, can dogs eat green scallions?

Unfortunately, dogs cannot eat scallions as they are toxic and can be life-threatening. In fact, scallions and green onions are one of the most dangerous human foods that you should never give your dog. To be safe, always ensure all green onions and products containing onions stay away from your dogs.

In this article, we will discuss if dogs can consume green onions, green onion toxicity, and everything else you may need to know about feeding your dog with green onions. Read on to find out why green onions are said to be dangerous and what will happen if your dog eats green onions.

Can Dogs Eat Green Onions?

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Again, no! Green onions are not safe for dogs. This is because they contain a substance called thiosulfate that dogs wonโ€™t be able to digest. After all, they donโ€™t have enzymes for it.

Furthermore, green onions also contain a substance called N-propyl disulfide. This substance attaches itself to the dogโ€™s red blood cells and tricks the body into thinking that the red blood cells are a threat. As a result, the body attacks them, causing damage through a process known as hemolysis.

What Are Green Onions?

Green onions, also known as scallions, are members of the Allium family. They are closely related to shallots, chives, garlic, and leeks. All green, white, and red onions are toxic to dogs. However, garlic is the most potent in the Allium family.

Can Dogs Eat Cooked Green Onions?

While green onions might not be toxic to humans, avoid feeding onions to your dog, regardless of whether they are cooked or raw.

Cooking onions wonโ€™t have any impact on the toxicity of onions. Cooked onions are still dangerous to dogs since they still have a toxic effect on the red blood cells. All green onions are toxic, whether cooked, fresh, or dried.

Now, letโ€™s take a closer look at the toxicity of green onions in dogs and things you can do in case your dog ingests green onions.

How Dangerous Can Scallions Be?

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While in some harmful substances for dogs like grapes, the toxicity is still debatable, with onions, the answer is very clear. 

The N-propyl disulfide chemical in green onions is a sulfur compound and can be very dangerous to dogs. This chemical is said to cause oxidative damage as it attaches itself to the oxygen molecules in the dogโ€™s red blood cells.

As a result, the red blood cells are unable to carry oxygen properly. As mentioned earlier, this compound will only trick your dogโ€™s body into thinking red blood cells are dangerous. This way, the body attacks the red blood cells through a process known as hemolysis.

When left untreated, hemolysis can cause hemolytic anemia. As a result, your dogโ€™s red blood cells will be destroyed faster than they are being made. This, in turn, causes serious symptoms and can even lead to death when left untreated.

Are All Parts Of The Green Onion Poisonous For Dogs?

All parts of green onions are dangerous to dogs. Whether raw or cooked, they should all be avoided at all costs. Furthermore, all types of onions are unsafe for dogs, including onion powder and other forms.

The American Kennel Club (AKC) states that it only takes 3.5 oz of onions for every 44 lbs of the dogโ€™s weight to cause harmful effects. This means that a dog with 50 lbs can easily get ill from a medium-sized onion.

What Happens When Dogs Eat Green Onions?

If you suspect that your dog has consumed a large number of onions, then you should call your vet immediately. If you have a smaller breed, then a very small amount of green onions could be very potent for your dog. 

However, when your dog has ingested the green onions just recently, Hemolysis can be prevented. Your vet may decide to induce vomiting using activated charcoal to eliminate the undigested herbs from the dogโ€™s gastrointestinal tract.

While inducing vomiting may sound easy, do not try to do it on your own. The veterinarian may then recommend a diet that is low in antioxidants and ask you to monitor the common signs of anemia.

For severe cases, your dog may need to be admitted to a veterinary hospital for several daysBlood transfusion and supplemental oxygen may be administered until the bone marrow is healthy enough to continue generating healthy and new red blood cells. Using medication and IV fluid therapy can also be used to clear some symptoms.

Still, even if it is in small amounts, you need to call your vet. Unfortunately, some symptoms donโ€™t appear right away. However, an early diagnosis can help lessen the amount of toxin your dog may absorb.

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What Are The Symptoms Of Green Onion Poisoning In Dogs?

Some symptoms of green onion poisoning may start to appear on the day your dog eats the onions. However, some symptoms may not appear right away and may take several days to be seen. 

Here are some symptoms you should watch out for according to AKC and ASPCA:

Call your vet immediately if you notice or observe any of the symptoms mentioned above. Still, even if the symptoms are mild, you need to contact or visit your vet.

How Much Green Onion Is Toxic To A Dog?

One of the main reasons why the green onions and other food items in the Allium family are very dangerous is because they donโ€™ require a lot of consumption for it to cause health problems in dogs.

Generally, the toxicity of green onions will happen when a dog eats slightly more than 0.5% of its total body weight in one go. In simple terms, even a tiny amount of green onions can be harmful to your dogs.

Ideally, the smaller the dog, the higher the chances that your dog will suffer from a small bite of green onions. For example, eating a small-sized onion might cause serious symptoms to a small dog weighing 10 lbs but might not have any effects on a large dog weighing 150 lbs.

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Is There An Amount Of Green Onions That Is Safe For Your Dog?

As mentioned, it only takes 0.5% of the dogsโ€™ body weight for the onions to be a toxic amount. This is why there are no amount of green onions that are safe for dogs to consume

It is frightening how hemolytic anemia can slowly build up in the blood over a long period of time. This means that if you continuously give your dogs a small piece of green onion, the toxicity will build up in their system, and eventually, the symptoms will start to occur.

Time is the determinant factor before you start seeing the symptoms with any amount of green onion your dog eats. Note that the onion powder is more potent or toxic than the actual onion, so avoid giving it to your dog at all costs.

How Is Onion Poisoning Treated?

When you visit your vet after noticing the symptoms, here are some steps your vet might follow to ensure your dog is treated;


Most often than not, your vet will do a urinalysis to determine if there is increased hemoglobin in urine. The vet will also do blood work to check on the Heinz bodies in the red blood cells.

Hemolytic anemia is normally detected using a microscopic test to look for Heinzโ€™s body on a blood smear. Once the veterinarians check the test results, the health history, and symptoms of your dog, they will diagnose the dog with onion toxicity.


When it comes to treatment, vomiting may be induced to get rid of onions that were consumed recently. Moreover, the vet may also do a stomach flush to remove the toxic and undigested portions.

The vet may administer activated charcoal to absorb the toxins and IV fluids to flush out the bloodstream and ensure hydration is maintained. For severe cases, blood transfusions and supplemental oxygen may be required.

Remember, time is of the essence when it comes to treating dogs suffering from onion toxicity. So, when you think your dog has eaten onions or anything that has onions, rush them to the vet immediately.


This is the last step of ensuring the sick dog goes back to its original healthy state. During prognosis, your dog will remain in the clinic for some time so that the vet can closely monitor it until the dangers are over. Remember, severe cases may need a long recovery time.

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How Do You Prevent Green Onion Poisoning?

When it comes to green onion poisoning, prevention will go a long way. Fortunately, dogs on their own do not enjoy the taste of green onions, making it easy to prevent the intake.

 Here are some of the best ways you can use to prevent green onion toxicity.

  • If you have a herb garden with onions planted, ensure the planted area remains fenced.
  • Ensure you properly dispose of the unused portions of onions.
  • Any food with green onions should be placed far away and out of the dogโ€™s sight or reach.
  • Do not give your dog food without being sure what is in it. Green onions are present in lots of meals.
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Pete Decker