Cat Tips

Can Cats Eat Onions?

Before you read anything else, the very important statement in this article is – NO, cats cannot and should not eat onions at all.

Yellow onions, sweet onions, red onions, white onions, shallots, scallions, etc. are all types of onions. There are hundreds of delicious recipes being made in every corner of the world using them. We humans clearly love onions. And with all the nutritional benefits they have, we should. But for cats, its different. Let us first understand if cats even like the taste and smell of onions.

Do Cats Like Onions?

While cats lack the taste buds that we have that make us like the taste of onions, it’s possible that your cat will be repelled by onions due to their smell alone. Some of the most common smells that cats are known to hate include citrus, vinegar, peppermint, pine, and onions. Given that cats have 40 times more olfactory receptors than us, it makes these smells more overwhelming to them.

Are Onions Good for Cats?

Let’s break down the nutritional content of onions.

A serving of 100 grams of onions consists of the following –

  • Calories: 31kcal

  • Carbs: 5.1g

  • Fat – 0.1g

  • Protein: 1.4g

  • Sugars: 5.1g

  • Fiber: 1.8mg

  • Sodium: 2mg

  • Vitamin C: 5mg

  • Niacin: 0.3mg

  • Potassium: 182mg

Onions are great for immune health, collagen production, and iron absorption. It is also an antioxidant. But these are all the benefits that we humans can extract from onions. Especially for men, onions help in increasing the sex appeal. But for cats, the case is the exact opposite.

What Happens When Cats Eat Onions?

Onions contain compounds called disulfides and thiosulphates which can be toxic to cats. The ingestion of onions can cause conditions including hemolytic anemia, Heinz body anemia, and methemoglobinemia which are all manifestation of damage to red blood cells. The result is lack of oxygen to the different parts of the body.

How Much Onion is Toxic to Cats?

The bulb, flower, and stem all are toxic to cats. Even the smallest quantity of any type of onion can cause harm to the digestive system of your cat. However, severe symptoms could start appearing if your cat ends up ingesting more than or equal to 5gms of onions per kilo of its body weight.

To identify if your cat is suffering from onion toxicity, you should be looking out for the following symptoms –

  • Excessive drooling

  • Vomiting

  • Diarrhea

  • Pale colored gums

  • Physical collapse

  • Pain in the abdomen

  • Weakness

  • Lethargy

  • Elevated heart rate

  • Elevated respiratory rate

Learn more about signs of poisoning in pets.

Similar Vegetables That Are Toxic to Cats

The list of toxic vegetables includes garlic, chives, and leeks. In fact, garlic is 5 times more poisonous as onions to cats. You need to make sure that all of these are kept away from your cat. That being said, here are a few vegetables cats can eat.

Is Cooked Onion Okay For Your Cat?

No. Onions in any form are not okay. While your cat may repel the onion in its raw form because of the pungent smell and strong taste, it is possible that it puts its paws on your pizza with onion in the sauce, or chicken tikka masala with onion and garlic powder in it, or the thousands of other dishes where onion is used in powder or paste form. All of them are to be avoided for your cat.

What To Do After Spotting Symptoms of Onion Poisoning?

While you may not see the symptoms right away, the symptoms could take a few days to appear. You need to keep checking every now and then if you have the slightest doubt that your cat has ingested onion in any form. In case you spot the above symptoms or you see your cat eating onions in front of you, you should go to the vet immediately. Time is of the essence here. It is important that the treatment is started at the earliest to help avoid major complications. The vet may suggest a complete blood count, blood chemistry profile, and urinalysis which could show abnormally low levels of red blood cells in your cat’s body. The vet’s reaction is based on your description of the symptoms. So, make sure you are accurate and as clear as possible.

Will My Cat Survive Onion Poisoning?

Onion toxicity can be fatal, especially if the cat has ingested more than 0.5% of its weight of onion. A delay inveterinary care may result in fatality or severe consequences.

How Long Can It Take for Cats To Recover From Onion Poisoning?

Research shows that 25% of the infected cats recover within 2 hours of infection, given proper veterinary care is available. It is advised that home remedies to be avoided and a vet should be consulted before doing anything on your own.


Several human foods that are safe and even good for your cat to eat. Onions are not one of them. They belong to the allium family and are highly toxic to cats. Do not try to feed any amount, any form, any type of onion to your feline friend. You, by the way, go ahead and eat your onions. They can be really good for you.

Happy mood and health to your purry friend and lots of love and licks to you! (Licks by your cat).


The information presented in this article is for educational and informational purposes only and does not constitute or substitute for the advice of your veterinarian.

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