Is Cats Safe?
Is Onion Safe for Cats?
No — Onion is toxic to cats.
Onion is listed as toxic to cats by ASPCA Animal Poison Control. The toxic component is N-propyl disulfide. Cats metabolise many plant and chemical compounds poorly, so keep Onion away from your cat and treat any exposure seriously.
| Scientific name | Allium cepa |
|---|---|
| Family | Liliaceae |
| Category | Plants |
| Toxic principle | N-propyl disulfide |
Signs to watch for in cats
- Vomiting
- Breakdown of red blood cells (hemolytic anemia, Heinz body anemia)
- Blood in urine
- Weakness
- High heart rate
- Panting
If your cat may have been exposed to Onion:
- Don't wait for symptoms; don't induce vomiting unless a professional tells you to.
- Note what and how much, and take any packaging with you.
- Call your vet or a 24/7 line now — Pet Poison Helpline 855-764-7661 · ASPCA 888-426-4435.
Other Liliaceae plants
Plants in the same family (Liliaceae) are easily confused with Onion — check each one:
Cat-safe alternatives
Browse all Plants for cats · or check another item.
Frequently asked questions
Is Onion toxic to cats?
Yes. Onion is reported toxic to cats by ASPCA Animal Poison Control. Keep it away from your cat.
What are the symptoms if a cat is exposed to Onion?
Reported signs include: Vomiting, Breakdown of red blood cells (hemolytic anemia, Heinz body anemia), Blood in urine, Weakness, High heart rate, Panting.
What makes Onion toxic to cats?
The harmful component reported for Onion is N-propyl disulfide. Cats metabolise many such compounds poorly, so even small exposures can cause problems.
How much Onion is dangerous to cats?
There is no established "safe" amount — sensitivity varies by cat, and small exposures can still cause signs. Treat any exposure as potentially serious rather than waiting to see how much was involved.
What should I do if my cat ate Onion?
Contact your vet or a 24/7 animal poison line right away: Pet Poison Helpline (855-764-7661) or ASPCA Animal Poison Control (888-426-4435).