Are Onions toxic to cats?

High severity

Yes, Onions are highly toxic to cats. Exposure can cause serious illness and needs prompt veterinary attention.

Symptoms to watch for

nausea
oral irritation
drooling
abdominal pain
vomiting
diarrhea
lethargy
pale gums
increased heart rate
increased respiratory rate
weakness
exercise intolerance
collapse

How vets treat it

Immediate veterinary consultation is required for decontamination and supportive care for anemia and gastroenteritis.

Why it's dangerous

Toxic compounds cause oxidative damage to red blood cells, leading to their rupture and subsequent anemia, while also causing gastrointestinal irritation.

Toxic compound: disulfides, thiosulfates

Good to know

Garlic is 5 times more potent than onion. Japanese dog breeds (Akita, Shiba Inu) and cats are more sensitive. Signs may be delayed for several days.

Sources

Pet Poison Helpline

This page is informational and is not veterinary advice. If your pet has been exposed to something risky, contact your vet or an animal poison control line right away.

The StrawPaw Team · How we prepare our guides

More substances toxic to cats

Full answer in the food guide: Can cats eat onions and garlic? → Rhubarb High severity Star Fruit High severity Poppy Moderate severity THC / Marijuana Moderate severity Everything toxic to cats →

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