Which plants are toxic to cats?
Quick answer
Many common houseplants and garden plants are toxic to cats, and a handful — most notably true lilies — can be fatal.
The full answer
The two groups owners most often confuse are the true lilies, which can cause kidney failure, and the calcium oxalate plants, which are intensely painful but rarely deadly.
Because cats groom themselves constantly, exposure is not limited to chewing. Pollen on the fur, a splash of vase water, or a nibbled leaf that is then swallowed can all be enough, which is why prevention is far easier than treatment.
True lilies: treat any exposure as an emergency
The true lily family (Lilium and Hemerocallis) includes Easter, Asiatic, tiger, day and stargazer lilies. Every part is toxic — pollen, leaves, petals, stamens and even the water in the vase.
Ingesting a tiny amount can cause acute kidney failure, and a cat that brushes against a lily and licks the pollen off its fur is also at risk. Call your veterinarian or a pet poison hotline immediately rather than waiting for symptoms, because kidney damage often becomes visible only hours later, when treatment is much harder.
Calcium oxalate plants: painful rather than fatal
This group contains insoluble calcium oxalate crystals: philodendron, pothos, peace lily, monstera (Swiss cheese plant), calla lily, dieffenbachia and ZZ plant. Chewing them causes intense burning and irritation of the mouth and throat.
Typical signs are drooling, pawing at the mouth, vomiting, swelling of the lips and tongue, and difficulty swallowing. These poisonings are distressing but rarely fatal. Rinsing the mouth with water and offering milk or plain water to drink is sometimes advised, but always call a vet or poison line first for guidance.
Other toxic plants worth knowing
Common toxic plants also include sago palm, which can cause severe liver failure, oleander and foxglove, which affect the heart, and azalea, rhododendron and kalanchoe, which cause vomiting and heart rhythm problems.
Tulip and narcissus bulbs, aloe vera, ivy, yucca, autumn crocus and castor bean are on the list too. Bulbs are often the most concentrated part of the plant, which matters if your cat digs in plant pots or in the garden.
Signs of plant poisoning and what to do
Watch for drooling, vomiting, diarrhoea, pawing at the mouth, swelling of the face or tongue, wobbliness, trembling, breathing difficulty, dilated pupils, collapse or a sudden change in behaviour. Some plants cause only local irritation; others act on the heart, liver or kidneys with no early signs at all.
If you suspect your cat has eaten a plant, move the cat away, keep a sample or photograph of the plant and the chewed leaves, note the time, and contact your vet or a 24-hour animal poison control line. Do not wait for symptoms, and do not induce vomiting unless a professional tells you to.
Cat-proofing plants at home
The safest approach is to keep toxic plants out of the house entirely. If you want to keep them, place them in a room the cat cannot access, and remember that hanging baskets are not protection — cats climb and jump.
Blocking access to soil with large stones or mesh helps with diggers, and placing plants on high, narrow shelves only works if the cat has no route to them. Training a firm no and offering a pot of cat grass as a permitted alternative also reduces the urge to nibble houseplants.
Checking whether a plant is safe
Common names are unreliable, as peace lily and calla lily are not true lilies, and several different plants are all called by the same nickname. Use the botanical name to check a plant against a reputable toxic plant database or ask your vet.
When buying a plant, ask the seller for the species name and look it up before bringing it home. Indoor plants that are generally considered cat-safe include spider plant, Boston fern, areca palm, calathea and most true succulents such as haworthia, though even safe plants can cause mild stomach upset if eaten in quantity.