Is this plant toxic to my cat?

Lilies, the first thing to know

If you only take one thing away from this page, let it be this: lilies of the genus Lilium and daylilies (Hemerocallis) can cause acute kidney failure in cats. Nibbling a leaf, licking a little pollen off its fur or drinking the vase water is enough. They are very common flowers in gift and supermarket bouquets, so the risk comes into the house without anyone deciding it. With a cat, the sensible thing is not to have them, neither in a pot nor in a vase, and to warn anyone who gives you flowers.

If it has bitten a lily, it is an emergency even if it seems fine

At first you may notice nothing, or just some vomiting and drooling, and that is misleading. The kidney damage appears later, and early treatment, within about 18 hours, makes the difference to the outlook. So do not wait to see symptoms: if you suspect it has touched a lily, go to the emergency vet with the plant or a photo. The same goes for the others in the highest category, such as sago palm, oleander, lily of the valley or azalea, which affect the heart, the liver or the nervous system.

What each level means

Very dangerous is what can cause serious harm or death even in small amounts. Toxic groups together very common houseplants, such as pothos, monstera, dieffenbachia, philodendron, aloe, snake plant, ficus or tulip, daffodil and hyacinth bulbs, which usually cause mouth irritation, drooling, vomiting or diarrhoea. Mild means passing stomach upsets: this is where the poinsettia sits, much less dangerous than people say. And non-toxic is what the ASPCA considers safe, such as calathea, spider plant, kentia palm, phalaenopsis orchid or peperomia.

Where the classification comes from, and misleading names

The basis is the ASPCA list of plants toxic and non-toxic to cats (the ASPCA is the American animal welfare society), which is the reference most vets use. Common names are the weak point: they change from one area to another and are sometimes confusing. Alstroemeria is sold as Peruvian lily and, despite the name, it is not a lily and it is not toxic. The other way round, some plants with innocent-sounding names are toxic. If in doubt, look for the scientific name on the pot label, which is what really identifies the plant.

Non-toxic does not mean it can eat the whole thing

A plant being safe means it does not poison, not that eating it by the mouthful will not upset it: any plant in quantity can cause vomiting or diarrhoea. Putting plants up high is not enough either, because a cat can reach almost anywhere. What works best is giving it an alternative: a pot of cat grass (sprouted oats, wheat or barley) that it can nibble to its heart’s content usually makes it leave the others alone. And watch out for fertilisers, insecticides and slug pellets on the terrace, which can be more dangerous than the plant itself.