Which essential oils are toxic to cats?

Cats are particularly vulnerable to essential oil poisoning, and veterinary toxicology sources warn that exposure can happen through skin contact, ingestion, or inhalation, including from diffusers. Oils commonly identified as toxic or high-risk for cats include peppermint, cinnamon, clove, eucalyptus, tea tree, citrus oils such as lemon, and ylang-ylang. Pet Poison Helpline also lists wintergreen, sweet birch, pine oils, and pennyroyal among oils known to cause poisoning in cats.

So your list includes several oils that are indeed commonly treated as unsafe for cats, such as cinnamon, clove, eucalyptus, lemon, peppermint, tea tree, and thyme. I would be cautious about presenting a definitive list without a vet disclaimer, because risk depends on the specific oil, concentration, route of exposure, and the cat’s health. Signs of poisoning can include drooling, vomiting, wobbliness, tremors, breathing trouble, low body temperature, and liver problems.