There are many popular house plants, and even common garden plants, that are considered toxic to our furry, fluffy or feathery friends – be they cats, dogs, hamsters, ferrets, rabbits, horses, birds…

But very few have the devastating effect that true lilies can have upon cats.

I have to admit – lilies are one of my favourite flowers. I have loved them for as long as I can remember, way before I discovered ranunculus, anemones and dahlias. My parents still have some going strong in their garden that I planted back in 2007, when I worked in a garden centre. However, I will not have true or day lilies around my cats. Ever. Full stop.

Why not? I’ll admit, I do take the odd risk with other “toxic” plants in the house, and it’s really important to know your cat(s) and the effects the plants can have on them if they are ingested. If you’ve got a cat who is a plant-chewer, I’d advise to at least do a Google search while in the shop before you buy new plants because it’s surprising which ones can cause issues. The effects of toxic plants can range from mouth irritation to full on organ failure. Here, only Rose has a go at plants very occasionally, and she’s happy enough to leave them alone if there’s cat grass around. (The biggest problem for my house plants is being used as a toilet, but that’s a different issue!)

So what’s the problem with lilies?

Not to be a scare-mongerer but lilies can cause acute renal failure resulting in death if ingested. Unlike a lot of other plants, EVERY SINGLE PART of the lily is highly toxic – the bulb, leaves, flowers, stamen, even the pollen. Just brushing against a lily, getting pollen on its coat, and then cleaning it off can cause a cat to ingest enough pollen to be in complete kidney failure within 36 hours.

Even the water in a vase of cut lilies has proven fatal.

So far, research has not pinned down the exact dose it takes for lilies to kill a cat, but even chewing on a leaf has been enough to cause death in some cases.

It is impossible to over-stress just how toxic lilies are to cats and this is why, even though most of my cats don’t nibble on plants, I will not have lilies from the genera Lilium (true lilies – the typical, fragrant, 6 tepal, star-shaped beauties) or Hemerocallis (day lilies) in my house or on my balcony, even as cut flowers If you are gifted lilies, or have some at home, make sure they are out of reach of your cats, especially if they’re inclined to eat plants, and cut out the stamens to remove the danger of pollen getting onto your cats’ coats. For me, personally, lilies are simply not worth the risk.

Are all lilies so deadly?

There are many types of plants that have the name “lily” in them, but not all of them are true lilies, and few of them are fatal if ingested.

As I said, lilies from the genera Lilium and Hemerocallis can cause kidney failure in a very short time if ingested.

Lilies from the genera Convallaria (lily of the valley), while not affecting the kidneys, contain potent cardiac glycosides including Convallatoxin, producing toxic effects similar to those of Digitalis (Foxgloves – which many of us know to be toxic to humans as well). Cardiac glycosides irritate the gastrointestinal tract and cause an abnormal heartbeat, which can prove life-threatening. Another plant which is a definite NO-NO in this house.

Plants from the Spathiphyllum (peace lilies) and Zantedeschia (calla lilies) genera are not true lilies and do not have the same extremely toxic effects, but that doesn’t mean that they are completely harmless either. Both peace lilies and calla lilies are considered mildly-moderately toxic as they contain calcium oxalate crystals which can cause skin irritation, irritation in the mouth and nausea when ingested. Although most symptoms subside in a relatively short time, and most cats learn their lesson, in extreme cases, chewing and ingestion may cause swelling of tissues in the mouth and throat, obstructing breathing. Thankfully, they do not cause kidney failure. I have one very large peace lily in my house, which I have had for several years living happily on top of the fridge, without any problems – until Fantasmino arrived and started using it as a bathroom. It is now outside in the corridor of my condominium. If your cat is a plant-nibbler, these plants are probably ones to avoid, just in case.

One “lily” that you can happily have around the home as it is considered non-toxic for both cats and dogs are Canna lilies – again, not true lilies but guaranteed to brighten up any home or garden without being a cause for concern at the same time. Alstroemeria, sometimes called the Peruvian lily, is also considered non-toxic, although ingestion of very large amounts will cause stomach problems due to the presence of tulipalin A.

So what should I do as a cat carer and lily lover?

At the end of the day, we all have to do what is right by us, but also what is right for the furry friends we bring into our lives and take responsibility for. We need to protect them from danger, as is reasonably possible, and for me, that includes not bringing in extremely toxic plants.

If you want to keep your lilies and your cats, make sure the stamens are removed, consider putting wire “cages” around any pots or garden plants to limit contact with the cats, and keep an eye out for any nibblers, especially if you bring in a new cat.

If you even suspect lily ingestion or poisoning, go straight to an emergency vet, no questions asked. The sooner intervention happens, the greater the chance of recovery.