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Can Cats Eat Green Onions? Will They Make Your Furry Friend Cry?

Can Cats Eat Green Onions? Will They Make Your Furry Friend Cry?

There’s hardly a pet parent in the world who hasn’t been in this situation before. You look over at your four-legged friend and notice she’s munching on something. “What on earth is that!?” You run over and investigate the inside of her mouth. “Can cats eat green onions!?”

No, they actually can’t. Green onions are pretty much the worst thing you can find in your cat’s mouth. According to our friends at the ASPCA (American Society for the Prevention of Cruelty to Animals), green onions can even be fatal to your cat.

While that sounds incredibly scary, you might be comforted by the fact that your furry friend isn’t likely to scavenge and snack on something she doesn’t like. And trust me, uncooked green onions couldn’t be further down her “tasty treats to steal from mom” list.

On the other hand, cooked green onions smothered with butter and drizzled with paw-licking gravy could seem like something she would enjoy munching on when she’s looking to cause some trouble. Not that she’s ever looking to cause anything else.

What’s even worse than that, green onions (and other types of onions) are often an ingredient in store-bought human food, baby food, and not-so-often, other pet food. You don’t have to worry about cat food for obvious reasons, but it doesn’t hurt to throw a quick glance at the ingredients.

You weren’t expecting this answer when you decided to look up “can cats eat green onions,” were you? Well, there’s nothing stopping you from scrolling down and reading everything you need to know about the complicated relationship between onions and cats.

So, can cats eat green onions?

Can Cats Eat Green Onions? Will They Make Your Furry Friend Cry?

Let’s start at the beginning. Green onions are a member of the Allium family. Along with garlic, shallots, scallions, spring onions, chives, and leeks, they probably make for some of the most used ingredients in your kitchen.

And if you’re a pet parent, you might be able to understand why that’s a pretty unfortunate coincidence. And if not, let’s get a bit more specific. Every single member of the Allium family contains disulfides and thiosulphates.

These two incredibly difficult-to-pronounce compounds are responsible for the whole “onions can seriously harm your cat” thing. And how do they do that? Well, they weaken your cat’s red blood cells that circulate throughout her body. Eventually, they end up bursting.

Once that happens, your cat becomes at risk of developing certain conditions known as hemolysis, hemolytic anemia, Heinz body anemia, and methemoglobinemia. While these conditions might sound like a bunch of words you’re not familiar with, they’re dauntingly dangerous.

And that’s not all… On the off-chance that your cat doesn’t have a sensitive digestive system, she might get away with just a mild case of onion poisoning or onion toxicity. There’s nothing mild about seeing your precious pet sick, but it’s slightly better than the other option.

So, it’s safe to say that cats can’t eat green onions (or any other type of onion for that matter). Even a small amount of onion can lead to some pretty dangerous side effects. Can you imagine what large quantities would do to your cat’s body? Let’s talk about that!

How many green onions can cats eat?

How about none!? Unfortunately, green onions can cause such damage to your cat’s body that it doesn’t even matter how much she manages to eat before you snatch it out of her mouth. Even a small amount of onion can lead to onion toxicosis.

Actually, we even have the statistics that suggest that around 5 grams of green onions per kilogram of your cat’s body weight could be enough to cause harm. Whether they result in gastrointestinal upset, toxicosis, or oxidative damage, they’re ominously dangerous.

And it’s pretty useless to discuss the lethal dose of green onions since it depends on every individual cat and the specific condition she’s in (health-wise) when the incident occurs. It’s safe to say that it’s your responsibility to keep all Alliums out of your cat’s reach at all times.

That being said, it’s also important to mention that green onions are dangerous in every form possible. Whether you’re using fresh, cooked, dried, powdered, or granulated onions, make sure you store them somewhere safe.

And if you’re a fan of those adorable kitchen gardens, it’s important to mention that the green onion bulb isn’t the only part of the onion that’s hazardous. The stalk, flowers, seeds, and leaves are equally threatening to your cat’s health.

So, to answer whether cats can eat green onions one more time… No, cats can’t eat green onions under any circumstances. Trust me, it doesn’t matter whether she eats a bunch of onions in one sitting or a bite of an onion a day over a longer period of time. It’s lethal, either way!

Can cats eat onion powder?

Can Cats Eat Green Onions? Will They Make Your Furry Friend Cry?

Onion powder is a type of seasoning that’s made from dehydrated, ground onions. Since cats can’t eat onions, you can make your own deductions and guess whether they can eat onion powder.

Jokes aside, if you’re someone who loves using onion powder in your kitchen, you’ll want to avoid putting it in anything you’re planning on sharing with your furry friend. You also want to store it on the highest shelf or the most hidden part of your kitchen cabinets. Why is that?

Well, fresh onions might not draw your cat’s attention while she’s sneaking around the kitchen. But, that onion powder you massaged all over your rotisserie chicken will. That’s the most dangerous thing about onion powder. There’s no way of telling whether your cat will eat something smothered in it!

Either way, cats can’t and shouldn’t eat onion powder. All those risks of onion toxicity, oxidative damage to your cat’s red blood cells, and anemia, also apply to accidentally (or purposefully) ingesting a bunch of onion powder. It’s better to be safe than sorry!

Can cats eat cooked onions?

And, you guessed it, the answer is still no. Cooked onions might even be more dangerous than fresh onions for the same reasons we mentioned a couple of paragraphs ago. While your furry friend might walk past fresh onions, cooked onions might draw her attention…

Especially when they’re prepared with something she really loves. A hamburger topped with fried onions, a steak with a side of sauteed onions, or even caramelized onions carefully placed on top of lamb chops… Who could resist all that deliciousness?

We all know that the cat lover within you can’t say no to those meows of desperation, but it’s your responsibility to make sure your cat doesn’t eat something she isn’t supposed to. You might think that cooked onions have less of an impact, but they don’t. They’re just as hazardous as the fresh ones!

What to do if your cat eats some green onions?

Don’t panic, but… You will have to react pretty quickly in order to provide your furry friend with the best supportive care possible. As mentioned before, if your cat eats even the smallest amount of green onions, she might experience some pretty gnarly repercussions.

One of the first things you might notice are symptoms of onion poisoning. They include anything ranging from vomiting, diarrhea, drooling, and pale gums, to more serious symptoms like elevated heart rate, elevated respiratory rate, and abdominal pain.

Remove any leftover green onions from your cat’s mouth (and out of her reach). Try to figure out how many green onions she’s already eaten, the type (fresh, cooked, powdered), and other information that might come in handy.

Contact your vet immediately, provide him with the necessary information, and keep him posted about your cat’s current condition. There’s also a possibility that you might have to take her to the nearest emergency animal center if her condition gets worse.

Either way, follow your vet’s advice to a T to ensure your furry friend doesn’t suffer any lasting consequences. And don’t forget to keep all things related to green onions out of your cat’s reach. At all times!


While we have repeatedly answered whether cats can eat green onions throughout the article, it doesn’t hurt to reiterate it once more: Cats cannot eat any part of green onions, in any form, under any circumstances!

To your four-legged friend’s demise, green onions can cause some serious damage to her digestive system even if she takes the tiniest of bites. Trust me, it’s so much better to stay on the safe side and hide this green goblin out of her paw’s reach. Good luck!

Can Cats Eat Green Onions?