Will a Small Amount of Onion Hurt My Dog? [BEWARE!]

Zack Keithy, our author, is a certified veterinarian technician (UC Blue Ash) for over 6 years (contact him here). The articles written here are based on his expertise and experience, combined with a review by our expert vet reviewers including Dr M. Tarantino. Learn more about us here.

Have you ever found yourself in the kitchen, prepping a tasty meal, and your loyal canine companion gives you those adorable, “share your food with me” puppy eyes? I mean, who can resist, right?

Will a small amount of onion hurt my dog? 

Well, it’s not something that can be answered in one sentence.

In this post, I’ll go into more details about this vegetable and our dogs and hopefully save you a lot of headaches!

Can Dogs Eat Onions?

When it comes to feeding your pup, one of the first things you’ll ever hear from another dog owner is probably “Don’t let your dog eat onions because they’re toxic for him.”

And in fact, the are absolutely right. Onions are VERY toxic to dogs.

I often see how wary most dog owners are of chocolates since it’s very dangerous to dogs, but the same should go for onions too.

But even though almost all dog owners already know the danger of onions to dogs, some still ask whether dogs can eat onions.

No, dogs cannot eat onions.

A tiny amount might not hurt it, but, honestly, it’s better to be safe than sorry.

Will a Small Piece of Onion Hurt My Dog?

How small are we talking about?

A small piece of onion (like a diced one) won’t likely hurt your dog. But of course, you’ll still need to be watchful.

If your dog constantly eats a small piece of onion, the toxin coming from it will only build up in your dog’s body no matter how small each piece is.

When this happens, your dog will surely feel countless symptoms from onion poisoning.

How Much Onion Will Hurt a Dog?

How much is safe and how much is too much?

That’s the kind of question concerned dog owners have in their minds whenever they’re thinking about onions.

The AKC warns dog owners that 100 grams of onion per 20kg of a dog’s body weight can already cause harm.

Let’s say your dog weighs 60kg. That means it can only have less than 300 grams of onion. Any more than that and it can already hurt your pup.

You’re probably thinking how hassle it is to do the math first before letting your dog eat onion.

Sad to say, there’s no other safe way to feed your dog some onion. You really have to do the math the right way lest you hurt your poor doggy.

Again, I would recommend avoiding this situation totally in the first place.

Are Onions Toxic to Dogs? Why Are Onions Toxic to Dogs?

Onions are VERY toxic to dogs. The effects it can have on your dogs are unthinkable.

From lethargy to fainting, you really have enough reasons not to let your dog near any onion.

But why exactly are they toxic to dogs?

Bear with me please because I have to be medically scientific here so you’ll know why exactly onions become a big NO to dogs.

You see, an onion has a toxin called N-propyl disulfide. It’s an organic compound that could destroy your dog’s red blood cells.

When the red blood cells get broken down, the really bad thing happens because canine anemia will occur in your pup.

The N-propyl disulfide from onions actually affects your dog’s red blood cells by latching onto the oxygen inside them. 

This makes it hard for the cells to carry oxygen, and it even confuses your dog’s body into treating the cell as a threat. 

At the end of all these, the red blood cells break down, and anemia will settle in.

Can the Method of Preparation (Chopped, Sliced, Cooked, Etc.) Affect the Level of Toxicity?

The onion’s level of toxicity will stay the same no matter how you prepare it for your dog.

Raw or cooked; chopped, sliced, or whole; cooked or powdered. However the onion is prepared will still and always be harmful to your pup.

I’ve mentioned that dogs can eat onions in small amounts, but if I were you I’d still be cautious. 

How Long After Eating an Onion Will a Dog Get Sick?

Your dog will get sick within 24 hours after eating an onion. But this will mostly depend on his weight and how much onion he has eaten.

Some dogs who have a higher tolerance for onion typically get sick around 1 to 3 days. 

If you ever suspect your dog has eaten an onion, watch closely for any unusual behavior because he’ll most likely experience unpleasant effects.

What Parts of an Onion are Toxic to Dogs?

Every part of an onion is toxic to dogs. From its leaves to its very juices and flesh is harmful to your dog.

You may think it’s safe for your dog to eat the leaves of an onion since they aren’t actually called onions, just leaves.

Well, you got it so wrong because leaves are just as toxic as their flesh.

Even powdered onion which no longer has the appearance of an onion is still toxic to dogs. 

What Are the Symptoms of Onion Toxicity in Dogs?

Onion toxicity usually results in anemia among dogs. 

Hence, when watching out for symptoms of onion toxicity, you’re really looking for symptoms of canine anemia. 

If your dog has eaten an onion, check for pale gums and reddish urine.

Your dog will also feel lethargic or weak because his red blood cells are breaking down, causing his body to have a hard time letting oxygen pass through his system.

In a more severe case, dogs will have fainting episodes and loss of appetite.

Onion toxicity works secretly. Some dog owners will notice the symptoms too late for them to save their dogs.

To avoid such a heartbreaking incident, make sure your dog doesn’t have any access to onions.

And if he ever managed to get his mouth on some, monitor him as closely as you can for the next 24 hours.

What Should You Do if Your Dog Ate an Onion?

Keep the onions away

Your dog doesn’t know how harmful an onion is for him. If he ate an onion, he’d likely want to have more.

Hence, you have to keep the other onions away from his reach.

If he gets another mouthful of an onion, everything will go out of hand since the toxicity level will already be too high for his little body to handle.

Wipe any onion juice or powder off the floor as he may lick it too!

Know how much onion your dog has eaten

If your dog has eaten too much onion, you have no time to waste before bringing him to the vet.

That’s why you have to know how much onion your dog has eaten so you’ll be able to decide what to do next.

Knowing the amount of onion your dog has eaten will also help the vet decide what treatment to give your dog.

Ring the vet

Don’t try any home remedies at home without calling your vet first. Don’t induce vomiting in your dog either!

Talk to the vet and share what exactly happened to your dog and how much onion he has eaten.

If your vet tells you to bring your dog to the clinic, quickly do so.

How is Onion Toxicity in Dogs Being Treated?

If your dog has eaten an onion only a few hours ago, the vet will likely just induce vomiting.

If it comes out successfully, the vet will then administer activated charcoal.

When your dog ingests the activated charcoal, it’ll attach to the toxins in his gastrointestinal tract. This will stop your dog’s body from absorbing the toxin any further. 

I don’t recommend you administer activated charcoal to your dog. It’s best to let the vet do it to avoid lung complications on your dog’s part.

If onion toxicity is in its worst condition, your dog will have to go through countless blood work to check his red blood cells.

If your dog’s red blood cells are starting to get broken down by the toxins, he’ll have to be hospitalized.

Severe onion toxicity usually results in anemia. And if your dog is diagnosed with it, he’ll need oxygen supplements and vitamins that’ll boost his iron.

I don’t wanna scare you but some dogs even have to go through blood transfusion if their anemia gets out of hand.

That’s how HARMFUL onions can be to your dog.

Can the Effects of Onion Poisoning in Dogs Be Treated at Home or is a Visit to the Vet Necessary?

The usual way to treat the effects of onion poisoning in dogs is to induce vomiting. And it’s something you shouldn’t do on your own at home.

A visit to the vet will make things easier and safer since the vet will know exactly what to do.

Some treatments for onion poisoning also include injection and administering activated charcoal.

Like inducing vomiting, these treatments are also very unsafe to do at home. So I’d say a visit to the vet is necessary to treat the effects of onion poisoning in your dog.

Can a Dog Recover From Eating Onions?

Most dogs recover from mild onion poisoning within a couple of days. 

If your dog has ingested a little too much toxins, don’t worry because he’ll still be able to recover from it with proper medical treatment.

Just make sure you bring him to the vet and you follow everything the vet has suggested to you.

With all the advancements we are making in the field of science and medicine? There’s no doubt a dog can surely recover from eating onions.

Perhaps some dogs may have to suffer from other doggies, but so long as they receive excellent care, they’ll push through.

How to Prevent Your Dog From Eating Onions?

The most obvious way to prevent your dog from eating onions is to keep onions away from him.

Place onions in a sealed jar or kitchen cabinet where your dog won’t be able to reach them.

You shouldn’t also let your dog eat table scraps since we humans really love adding onions to our home-cooked meals.

But if your dog’s diet consists of human food, make sure you don’t add any onion to its ingredients.

You also have to remember that onions are the staple ingredients for soups so avoid feeding your dog an already made soup! 

What Are Some Healthy Vegetables for Dogs?

With how sensitive your dog’s body is towards human food, I understand if you wanna know what vegetables are suitable for him.

The good thing for you is I’ve made a list of healthy vegetables your dog can eat! 

Treat him with some of these veggies for a healthier and safer meal:

• Boiled or steamed carrots
• Boiled or steamed green beans
• Boiled or steamed sweet potatoes/potatoes
• Brussel Sprouts
• Celery
• Broccoli – in small amounts, raw or steamed
• Celery
• Peas (except tinned peas)

Frequently Asked Questions (FAQs)

In Conclusion: Will a Small Amount of Onion Hurt My Dog

In the end, your dog’s well-being is paramount. 

While a tiny bit of onion may not seem like a big deal, it’s best to err on the side of caution. 

Stick to dog-friendly treats, and your loyal companion will thank you with endless tail wags and unconditional love.