Cats are not automatically allergic to rosemary, but some individual cats can be sensitive to it. Rosemary itself is considered non‑toxic to cats in small amounts, while concentrated rosemary essential oil is unsafe and should be avoided.

Safety of rosemary

• Fresh or dried rosemary is classified as non‑toxic for cats and is even used in small amounts in some commercial cat foods as a flavoring or preservative.

• If a cat eats too much rosemary, it may cause mild digestive upset such as vomiting or diarrhea, so moderation is important.

Allergies and sensitivities

• Cats are not inherently allergic to rosemary, but individual cats can develop sensitivities or allergic‑type reactions, including skin irritation, itching, or mild respiratory signs.

• If you notice vomiting, diarrhea, coughing, sneezing, redness where the cat contacted rosemary, or any breathing difficulty after exposure, stop using rosemary and contact a veterinarian.

Rosemary essential oil

• Rosemary essential oil is much more concentrated than the herb and is not considered safe for cats, even in small quantities.

• Ingestion or heavy inhalation of rosemary oil can cause drooling, tremors, lethargy, low heart rate, or seizures, and requires urgent veterinary care.

Practical advice

• Occasional light exposure to the plant or a tiny amount in food is usually fine for most healthy cats, but always introduce it gradually and watch for any reaction.

• Avoid using rosemary essential oil in diffusers, sprays, or on your cat’s skin or fur, unless a veterinarian has specifically recommended and supervised its use.