Is Basil Toxic to Cats and Dogs? (Ocimum basilicum)

ASPCA Animal Poison Control lists Basil (Ocimum basilicum) as non-toxic to cats and dogs. Non-toxic on that list means no poisoning is expected; a pet that eats a lot of any plant can still vomit or have an upset stomach.

If a pet may have eaten a plant, contact a veterinarian, ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661. Note what was eaten, how much and when, and bring a photo or a piece of the plant. Do not induce vomiting or give home remedies unless a professional tells you to.

Non-toxic covers poisoning, not everything. A cat or dog that chews a lot of Basil can vomit or have loose stools from the fibre, and fertiliser, pesticide residue or leaf shine on the plant is a separate risk. If your pet keeps chewing houseplants, the habit itself is worth a word with your vet.

• Aloe Vera
• Azalea
• Chrysanthemum
• Cyclamen

Toxicity lists are by species, and many houseplants look alike. Photograph the whole plant, a leaf close-up and any flower in even light; the app reads the species first, then you can check it here. If the species is uncertain, act as if it were toxic.

A cat that nibbles a basil plant is not poisoned by it: the ASPCA lists basil (Ocimum basilicum) as non-toxic to cats and dogs. Acton Animal Hospital adds the practical limits: eating a lot of it can still cause vomiting, diarrhoea or mild lethargy, dried basil is more irritating than fresh, and basil cooked with garlic or onions is a real risk because garlic and onions are toxic to cats.

So the plant on the windowsill is fine; the pesto on your plate is not something to share.

Mostly smell and texture, not chemistry. Acton Animal Hospital lists curiosity about the strong scent and crinkly leaves, boredom in indoor cats, and an instinct to chew greens that may help with hairballs. Basil is in the mint family, Lamiaceae (ASPCA), the same family as catnip, which is why people expect it to have a catnip-like effect. It does not; see the next section.

No. Catnip's effect comes from nepetalactone, which the ASPCA names as its active principle. Basil does not make it. A 2020 study in Science Advances, summarised by the Florida Museum of Natural History, found that the ancestor of the mint subfamily that includes basil, oregano, rosemary, lemon balm and mint lost the ability to make this class of compounds (iridoids) through a gene deletion 55 to 65 million years ago. Catnip later rebuilt the ability by a different route, about 20 million years ago. The museum puts the share of cats that respond to catnip at about two-thirds.

If your cat rolls in the basil, that is interest in a strong smell, not a catnip reaction. And note that catnip itself is not on the ASPCA's non-toxic list: it lists catnip as toxic to cats, with vomiting and diarrhoea possible when a cat eats a lot.

Yes, several common kitchen herbs are on the ASPCA's toxic list, even though basil is not:

• Oregano (Origanum vulgare hirtum). Toxic to cats, dogs and horses; gastrointestinal irritant; mild vomiting and diarrhoea.
• Mint (Mentha species). Toxic to cats, dogs and horses; essential oils; vomiting and diarrhoea with large amounts.
• Chives (Allium schoenoprasum). Toxic to cats, dogs and horses; can damage red blood cells (hemolytic and Heinz body anaemia), with blood in the urine, weakness, a fast heart rate and panting. The onion family is the serious one on this list.
• Catnip (Nepeta cataria). Listed toxic to cats; vomiting and diarrhoea, and sedation or stimulation depending on the cat.

The herbs we have checked that the ASPCA lists as non-toxic include basil and rosemary. If a cat has eaten chives or anything from the onion family, call your vet or ASPCA Animal Poison Control on (888) 426-4435.

No official ranking exists, but true lilies are the plants vets treat as an emergency: the ASPCA lists them as causing kidney failure in cats. Unlike basil, a lily in a vase is a reason to call a vet even if the cat only touched the pollen. See lilies and cats and our list of house plants safe for cats.

Acton Animal Hospital suggests moving plants to a high shelf or a closed-off area, offering cat grass as something the cat is allowed to chew, and adding enrichment so a bored indoor cat has less reason to chew plants. Grow the basil where the cat cannot also reach pots of chives, mint or oregano, which are on the toxic list above.

The sections above headed what happens when cats eat basil, why cats like it, basil versus catnip, toxic herbs, the most toxic plant for cats and growing basil with a cat were added on 2026-09-25. Research and drafting were done with the help of AI, and every figure was checked line by line against the sources listed on this page.