10 plants that can poison a cat (and the one that is deadliest)

Cats nibble plants. Some do it out of curiosity, some out of boredom, some because a leaf moved and clearly deserved it. Most plants are harmless, but a few are genuinely dangerous, and some of the most common ones in Spanish streets and gardens are on that list. Watch the short film above, then use this guide to check your home, balcony and garden.

Number one: lilies, the deadliest flower for cats

If you remember only one thing, remember this: lilies and cats should never share a home.

True lilies (Lilium: Easter, Asiatic, Oriental, stargazer and tiger lilies) and daylilies (Hemerocallis) are extremely toxic to cats. Every part of the plant is dangerous: petals, leaves, stem, pollen, and even the water in the vase. A cat can be poisoned just by licking pollen off their fur, and eating less than a single leaf can cause kidney failure within a few days.

• Pollen-free lilies are not safe. The whole plant is toxic, not just the pollen.
• Speed is everything. Treatment works best when it starts within hours, long before the cat looks ill.
• Check bouquets. Lilies are very common in shop-bought flowers and gifts. If someone gives you lilies, they go to a cat-free home.

Other plants with "lily" in their name (peace lily, calla lily) don't cause kidney failure, but they can irritate the mouth and stomach. Lily of the valley is a different story entirely (see below).

Nine more plants to keep away from cats

Oleander

Oleander (Nerium oleander) lines streets, roundabouts and gardens all over Spain. Every part of it is poisonous. It contains cardiac glycosides, substances that disturb the heart's rhythm, and it can cause severe vomiting, a slow heartbeat and death. If your cat goes outdoors, know where the nearest oleanders are.

Sago palm

The sago palm (Cycas revoluta) is a favourite in Mediterranean gardens and on terraces. It isn't a real palm, and every part is toxic, especially the seeds. It attacks the liver and can be fatal even with treatment.

Foxglove

Tall spires of purple, pink or white bells. Foxglove contains powerful heart toxins and is considered one of the most toxic plants of its kind.

Lily of the valley

Pretty white bells, popular in spring bouquets and wedding flowers, and dangerous: it contains heart toxins that can cause vomiting, a slow heartbeat, severe heart rhythm problems and seizures.

Yew

A common evergreen for hedges, parks and churchyards. The leaves and the seed inside the red berry are toxic and can cause heart failure.

Autumn crocus

This late-flowering bulb can cause severe vomiting, bleeding in the gut, liver and kidney damage and breathing failure. Don't confuse it with harmless spring crocuses: if you're not sure which you have, keep it away from your cat.

Azaleas and rhododendrons

Beautiful, popular, and toxic: they can cause drooling, vomiting, diarrhoea, weakness and heart problems.

Tulips, hyacinths and daffodils

The flowers are a risk, but the bulbs are the most toxic part. They can cause severe vomiting, diarrhoea and abdominal pain, and daffodils can also affect the heart. Keep bulbs out of reach, and watch cats who love to dig.

Kalanchoe

A cheerful, very common houseplant with small, bright flowers. It usually causes stomach upset, but larger amounts can affect the heart.

Signs that your cat may have been poisoned

Signs depend on the plant, but can include:

• drooling, pawing at the mouth, vomiting or diarrhoea
• not eating, hiding, unusual tiredness or weakness
• drinking and peeing more, or much less (lilies)
• a very slow or irregular heartbeat, wobbliness, tremors or seizures (heart-toxic plants)

Some cats look completely normal at first. With lilies, oleander, sago palm, foxglove, lily of the valley and yew, never wait for symptoms.

What to do right away

1. Go to your vet or the nearest 24-hour emergency clinic immediately.
2. Take the plant with you, or at least a clear photo and the plant label. Identifying it correctly saves time.
3. Tell the vet what your cat ate or touched, how much, and when.
4. If there is lily pollen on your cat's fur, stop them grooming it off and tell your vet.
5. Don't try to make your cat vomit at home unless your vet tells you to.

Cat-safe plants to grow instead

You don't have to live without greenery. These popular plants are listed as non-toxic to cats by the ASPCA:

• Spider plant (Chlorophytum comosum), which many cats adore
• Boston fern (Nephrolepis exaltata). Careful: asparagus fern is not a real fern, and it is toxic
• Areca palm (Dypsis lutescens) and parlour palm
• Calathea (prayer plant)
• Cat grass, grown especially for nibbling

"Non-toxic" means not poisonous, not that it's food. A cat who eats a whole fern may still vomit. And always check the botanical name on the label, because common names can be misleading.

His Majesty has tested the Boston fern personally. Verdict: excellent for napping.