Is Pennyroyal Oil Safe for Cats?
Why it’s a problem
Pulegone in pennyroyal oil destroys liver tissue in cats, and cats cannot clear its terpenes because they lack glucuronyl transferase. Poisonings have followed flea-repellent sprays and skin application, with cats grooming oil off their fur.
How to keep your pet safe
Never apply pennyroyal oil to a cat, its bedding, or anything in its environment, including as an insect repellent. Keep the bottle sealed away. Ask your veterinarian for cat-safe parasite control instead.
Warning signs to watch for
Drooling, vomiting, lethargy, weakness, bruising, pale or yellow gums, abdominal pain, seizures, collapse
When to call the vet
Contact a veterinarian or pet poison hotline immediately, even before symptoms start. Pennyroyal liver injury can be delayed and is often fatal once signs appear.
Common questions
Is diffusing pennyroyal around my cat safe?
No. Pennyroyal is among the most dangerous oils for cats and should never be diffused where a cat lives, even briefly.
Why is pennyroyal oil so much worse than other oils for cats?
It combines a potent liver toxin, pulegone, with terpenes cats cannot metabolize. That double hit is why exposures that seem small have been fatal.
More essential oils hazards for cats
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate or touched something concerning, contact your veterinarian or a pet poison hotline right away. In the US: Pet Poison Helpline (855) 764-7661, ASPCA Animal Poison Control (888) 426-4435 (fees may apply).