Can Cats Eat Onion?
Food-safety reference.
Short answer
No, onion is toxic to cats.
According to the U.S. Food and Drug Administration, which names this food among those dangerous to pets, our cat rating is toxic. Portion guidance: None. Watch for: Lethargy, anemia, vomiting, difficulty breathing. The same food is rated toxic for dogs; feline metabolism often differs, so do not transfer the dog rating. Ask your veterinarian about your own animal.
No. Onion is toxic to cats.
Cats are more sensitive than dogs; tiny amounts can be fatal
Food-safety rating slip
Cats can-eat rating TOXIC Onion
TOXIC · Vegetables · 20% cat-haz
- LEVEL toxic
- DOG toxic
- SHARE 20% haz
- RISK 3 risks
- BEN 0 benefits
- SYMP listed
- SRC U.S. Food and D…
- PHOTO Asparagus
Category photo peer: Asparagus (caution)
Cat rating for onion is toxic. Dogs: toxic. Vegetables neighbourhood compares 6 foods by hazard band. Band scores are ordinal (toxic=4 → safe=1), not clinical doses. Read with this food →
Category standing
Toxic on both the cat and dog charts
Cats and dogs share a toxic rating for Onion. Inside vegetables, 4 of 25 cat ratings are toxic. this is a household-wide keep-away, not a species-specific quirk.
Source for this food: U.S. Food and Drug Administration, which names it among the foods dangerous to pets. Portion, preparation and symptom detail on this page is our own editorial guidance.
Portion & Preparation
- Recommended Portion
- None
Risks & Warnings
- ⚠ Thiosulfates extremely toxic to cats
- ⚠ Even more sensitive than dogs
- ⚠ All forms: raw, cooked, powdered
Warning Signs
Lethargy, anemia, vomiting, difficulty breathing
If your cat shows these symptoms, contact your vet or call ASPCA Poison Control: 888-426-4435
Also Safe for Dogs?
One of the most common pet poisonings; onion powder especially concentrated
Full dog safety guide for Onion →🚨 Pet Poison Emergency
ASPCA Animal Poison Control
888-426-4435
24/7, consultation fee may apply
Other Vegetables for Cats
Read our methodology - how this data is sourced, computed, and verified.
PlainPetFood publishes an editorial food-safety compilation. When the FDA or ASPCA Animal Poison Control Center names a food as dangerous, that food's page links the source; other ratings are identified as editorial guidance. Its cat rating, portion, preparation notes and warning signs are rendered from the food-safety archive; a named FDA or ASPCA source is linked above when that authority names this food. See our editorial standards & corrections policy, report a correction, the methodology behind these numbers, or contact the editorial team. Data current as of August 29, 2026.