With caution — cats and rosemary
Fresh or dried rosemary in small leaf amounts is not acutely toxic to cats. The ASPCA does not list rosemary as toxic. However, rosemary contains camphor, a compound that is a CNS stimulant and can cause neurological symptoms including seizures in cats at meaningful doses. Rosemary essential oil is more concentrated and genuinely problematic. Rosemary extract (marketed as a natural preservative in pet foods) is used at low concentrations where it's generally considered safe — but the presence of rosemary extract in cat food has been debated in cats with epilepsy. Not a food to offer deliberately.
🏆 Pet Care Community Safety Score™ — Rosemary for Cats
"Rosemary sits in an interesting position: it's technically non-toxic on the standard pet toxicity lists, but it's not quite the innocent herb that some online sources make it out to be. The camphor content is real, and there's a genuine discussion in veterinary neurology about rosemary extract in cat foods and its potential to lower seizure threshold in epileptic cats. For a healthy adult cat with no neurological history, trace contact with rosemary herb is not a concern. I'd be more cautious about any concentrated rosemary product."
The straight answer
A cat nibbling a piece of rosemary from your herb garden is unlikely to experience any significant adverse effect. Rosemary is not on the ASPCA's toxic plants list for cats. But it is not cleanly "safe" in the way that, say, basil is — the camphor content gives it a more complex risk profile than the herb's benign reputation suggests. Most people encounter rosemary in cat contexts through two routes: herb garden access, and rosemary extract as a preservative in commercial cat food.
The camphor and volatile compound content
Rosemary (Rosmarinus officinalis, now reclassified as Salvia rosmarinus) contains a significant proportion of volatile aromatic compounds in its essential oil:
- Camphor (10–20% of essential oil): A bicyclic terpene with CNS stimulant properties. In humans and animals, camphor poisoning causes CNS excitation, including seizures, at toxic doses. The toxic oral dose of camphor in cats is not precisely established, but cats' reduced glucuronidation capacity means camphor metabolism is less efficient than in humans or dogs.
- 1,8-Cineole (eucalyptol): A terpene also found in eucalyptus oil, known for respiratory mucosa irritation at high concentrations
- Borneol and bornyl acetate: Additional monoterpenes with mild neurological activity
The concentration of these compounds in fresh rosemary leaves is much lower than in extracted rosemary essential oil. A cat chewing a few leaves receives a dose of these compounds well below the threshold for neurological effects in most cases.
The epilepsy concern
The most specific clinical concern with rosemary and cats is in epileptic patients. Research in veterinary neurology has raised the question of whether rosemary extract — used as a natural antioxidant preservative in many commercial pet foods (often listed as "natural flavouring," "rosemary extract," or "tocopherols from rosemary") — might lower seizure threshold in cats with pre-existing epilepsy.
This is not a settled question in the literature, and rosemary extract in pet foods is present at very low concentrations (typically parts per million). However, for cats with known seizure disorders, some veterinary neurologists recommend selecting cat foods without rosemary extract on the ingredient list. If your cat has epilepsy and you're selecting food, this is worth discussing with your vet.
Rosemary essential oil — different risk profile
Rosemary essential oil is a concentrated extract of the compounds described above, with camphor and cineole in much higher concentrations than fresh herb. Rosemary essential oil products — diffuser oils, aromatherapy blends, "natural" cleaning products, and some pet grooming products — pose a more significant risk than the culinary herb.
As with all essential oils used in the home, cats face the risk of: - Inhalation from diffusers - Dermal absorption and subsequent grooming ingestion - Direct skin contact from oil-containing products
Do not apply rosemary essential oil to cats or use rosemary oil diffusers in enclosed spaces where cats live.
Rosemary in Australian herb gardens
Rosemary is extremely commonly grown in Australian gardens — it's drought-tolerant, fragrant, and versatile. Most cats avoid it due to the strong resinous scent. The resinous texture of rosemary leaves also makes them physically unpleasant to eat. Occasional contact with the garden plant is low risk for healthy, non-epileptic cats.
🚨 My Cat Ate Rosemary — What Now?
Fresh rosemary leaf in small amounts is not an emergency. Rosemary essential oil exposure — direct skin contact or significant ingestion — call the Animal Poisons Helpline on 1300 869 738.
Signs that warrant a vet call:
- Drooling or oral irritation from chewing the resinous leaves. With significant ingestion: vomiting
- neurological signs in sensitive cats. Rosemary essential oil: more serious CNS and GI effects
If your cat ate a large amount or is showing the signs above: Don't wait — call immediately.
📞 Animal Poisons Helpline: 1300 869 738Available 24/7 across Australia. Have your cat's weight, breed and approximate quantity consumed ready when you call.
Frequently Asked Questions
Cold rosemary water (herb steeped in water) is a very dilute extract. Small incidental exposure is low risk. It is not a beneficial supplement.
For more on herbs and cats, see our guides to basil, parsley, and coriander, and our cat food safety hub.
📚 Sources & Further Reading
- ASPCA Animal Poison Control — Rosemary. https://www.aspca.org
- Burkhard PR, et al. Plant-induced seizures: reappearance of an old problem. Journal of Neurology 1999.
- Cornell Feline Health Center — Feline Epilepsy. https://www.vet.cornell.edu
- Australian Veterinary Association — Herb Safety for Cats. https://www.ava.com.au
