TailVilleWhy
Onions and their relatives contain sulfur compounds (such as N-propyl disulfide) that oxidize and rupture red blood cells, causing hemolytic anemia that can develop over several days. Cooking, frying or drying doesn't destroy the toxin, so onion powder in broths, sauces, soups and baby food counts too. Cats' red blood cells are especially vulnerable to this damage, so smaller amounts can cause problems.
How to give it / if eaten
If your pet ate onion or a dish heavy in onion, contact your vet or an emergency clinic right away. Anemia can show up days later, so your pet may need care even if it looks fine now. Note the time, the amount and the dish, and don't induce vomiting at home without a vet's instruction.
Watch for these signs
Early vomiting, diarrhea or drooling, then 1โ5 days later signs of anemia: weakness, pale gums, fast breathing, reluctance to exercise and red or brown urine.
FAQ
My dog lapped up some broth made with onion. Is that okay?
The toxic compounds dissolve into broth, so it isn't automatically safe. Even a small amount can matter for a small pet, so tell your vet how much was eaten and follow their advice.
Isn't onion safe once it's cooked?
No. Cooked, fried and powdered onion are all still toxic. Skip onion rings and any snacks or instant noodle seasoning made with onion powder.
General information only. Weight, age and health conditions change how a pet reacts, so ask your vet if you are worried.