Can Cats Eat Onions? Vet-Reviewed Risks & Safety Guide

Many pet parents treat their pets like children, and it can be difficult to deny them anything. Some foods are harmless and tasty treats for your beloved feline. But other foods can be unhealthy or toxic for your cat, even if they’re perfectly fine for humans to consume.

Onions are one of these foods. They have loads of health benefits for you, but for your cat, onions can be a fatal food as they are considered toxic. In this article, we’re going to take a look at why onions are toxic to cats and what you should do if your cat happens to eat an onion.

Why Are Onions Toxic to Cats?

Onions are toxic to cats ¹. Other members of the plant genus Allium, including garlic, chives, leek, and shallots, can also cause toxicity. These plants are considered toxic for cats because they contain compounds that can destroy your cat’s red blood cells. These cells are essential for life as they transport oxygen all over your cat’s body and carbon dioxide back to the lungs to be expelled.

Can Cats Eat Any Amount of Onions?

Even in tiny doses, onions can cause numerous health problems for felines. However, the severity of the issues your cat is likely to experience is dose-dependent. If your cat eats only a small amount of onion, then its reaction may not be too severe. That said, it doesn’t take much onion to cause a major reaction and potentially deadly consequences. This, coupled with the fact that onions don’t offer cats any notable health benefits, means that there’s no reason to actively incorporate onions into your cat’s diet.

Are Raw or Cooked Onions Safe for Cats?

In most cases, cats will be completely uninterested in raw onions. They are naturally averse to the smell and taste of onions, so it’s not likely for your cat to eat one raw. Generally, when a cat eats an onion, it is in some other food. Whether the onion is cooked, raw, powdered, dehydrated, or in any other form, the toxic principle is the same. It’s toxic for your cat, and any form of onion can cause the same health problems. Powdered forms of onion are generally the most concentrated and, as such, pose the greatest risk.

What About Other Plants in the Same Genus?

Onions are part of the Allium genus, which also includes other popular plants such as chives, garlic, and leeks. While these are delicious for humans, every plant in the allium family is toxic for your feline. If your cat eats any of these plants, the results will be similar. That said, garlic is far more toxic than onion, and cats are particularly sensitive to garlic poisoning.

Keep all of these out of your cat’s reach to prevent emergencies. If you decide to feed your feline food from your plate (a controversial topic in itself), take care to ensure that no garlic, onion, chives, or other Allium plants are used to season or flavor it.

What Should You Do if Your Cat Eats Onions?

One problem with cats eating onions is that the side effects can take days to kick in. It might seem like your cat is fine, but several days later, the severe signs might start to set in. At this point, it might already be too late.

Whenever you notice that your cat has eaten onions or other Allium plants, you should contact a vet immediately. They’ll likely want you to bring your cat in for in-person monitoring and treatment. Don’t try to induce vomiting for your cat at home.

Treating a Cat That Ate Onions

When you get your cat to the vet, they will begin by assessing your feline. The treatment's main goal would be to ascertain the extent of the onion poisoning in your cat and how they can help your cat feel better. There is no particular antidote for onion poisoning, so all treatments are purely supportive based on the signs your cat displays. That being said, you may notice your vet perform one or more of the following:

As with all poisonings, it is best to follow your vet's advice on care, treatment, and post-discharge instructions.

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Conclusion

Onions and other plants in the Allium family, such as garlic and chives, are highly toxic to cats. If your cat eats any form of these plants, including raw, cooked, powdered, dehydrated, or otherwise, the results will be unpleasant at best and fatal at worst. Hopefully, you’ll never have to deal with such an issue. But if you do find that your cat has eaten onion,contact your veterinarian immediately for treatment.

For more information on what cats can eat, check out:

• Can Cats Eat Bananas? 

• Can Cats Eat Honey?

Featured Image Credit: Couleur, Pixabay