Is Onion and shallot safe for cats and dogs?
| Species | Verdict |
|---|---|
| Cats | Toxic |
| Dogs | Toxic |
Severity: Severe
Read the full first-aid guide: what to do if your pet ate something toxic
The onion exposure that actually lands US dogs and cats in the ER is rarely a raw slice; it's the dehydrated onion powder packed into soup mixes, boxed broth, burger seasoning packets, and the crispy fried-onion topping on a Thanksgiving green bean casserole. Because drying concentrates the compound, a teaspoon of onion powder carries the punch of several fresh onions in one small spoonful, so a plain-looking casserole scrap or a dog that laps up leftover onion soup mix broth can deliver a bigger dose than the pet owner ever intended to share.
Facts and examples
- Onion, chives, garlic, and leeks (the Allium family) are all confirmed poisonous to dogs, cats, and livestock. (source, verified 2026-07-26)
- Dried and powdered Allium products contain a higher concentration of the toxic compound per unit weight than fresh forms because water content is removed; one teaspoon of garlic powder is equivalent to roughly eight fresh cloves (the same concentration principle applies to dehydrated onion). (source, verified 2026-07-26)
Verdict re-verified against vcahospitals.com, 2026-07-26 — confirmed unchanged. Source
This page is for general information only and is not veterinary advice, diagnosis, or treatment. If your pet is showing symptoms, or you think they ate or touched something dangerous, contact your veterinarian or a pet poison-control hotline immediately.
Last verified 2026-07-26