Ask if there is a cat before you send lilies

People do not set out to send a poisoned gift. What happens is that somebody orders flowers for a birthday, a hospital discharge or a funeral, in a hurry, thinking about the person rather than the household — and lilies are the default in exactly the arrangement where the recipient is least able to cope with a problem, which is the sympathy bouquet.

The result arrives at the door of someone who is grieving, who now has to identify every stem in it before they can put it down.

Two families of flower cause kidney failure in cats — true lilies and daylilies — and the word “lily” on a label does not tell you whether you have one.

The two that kill, and the ones that only sound like it

The dangerous ones are the genus Lilium — Easter, Asiatic, Oriental, tiger, stargazer — and the genus Hemerocallis, the daylily. A veterinary school’s own guidance and the ASPCA both treat them as poisonous to the kidneys, and the amount required is very small: less than a single leaf has been enough.

The daylily half of that is worth pausing on, because it is where this gets repeated wrongly. The tidy version people pass around is that daylilies are a completely different plant and are therefore fine. They are a different plant, and they are not fine. The veterinary position puts them in the same category as the true lilies, and a version of this advice that leaves them out is worse than no advice, because it sends somebody home relaxed.

Going the other way, several plants sold as lilies are not in either family and do not do this at all. Peace lilies and calla lilies contain calcium oxalate, which burns and swells the mouth — unpleasant, sometimes needing a vet, and a different order of thing entirely from kidney failure. Alstroemeria, sold as Peruvian lily and used as filler in a lot of bouquets, is listed as non-toxic by the ASPCA and as mildly upsetting by others; nothing treats it as a kidney poison.

That matters more than it looks. Somebody who has been told alstroemeria is “just as dangerous” and then finds out it is not learns something worse than a wrong fact — they learn that the warnings are inflated, and then they discount the one that was true.

Why pollen is the whole problem

People picture a cat eating a flower. That is not usually what happens.

Pollen comes off a lily onto whatever passes: the counter, the floor, a sleeve, and the cat’s own coat. Then the cat washes, which is what cats do for hours a day, and it goes in. There does not need to be a chewed leaf anywhere. The water in the vase carries it too, and a cat that drinks from vases has found the concentrated version.

Underneath that is a piece of cat biology that explains a surprising amount. Cats are short of an enzyme — UDP-glucuronosyltransferase — that other animals use to package up plant compounds and get rid of them. It is why a cat’s tolerance for botanical chemistry is so much narrower than a dog’s, and it is the same reason behind a warning that looks unrelated at first: essential-oil diffusers. The mechanism is identical, right down to the route. A diffuser throws microdroplets that settle on the coat, and the cat grooms them off.

So the instruction is not to put the lilies somewhere high. The cat gets to the high places, the pollen comes down on its own, and the plant has to be out of the house. Taking the stamens off is not a fix either: it removes one route and leaves the rest of the plant exactly as it was.

What a toxic-plant list cannot tell you

The standard advice is to check the ASPCA’s plant list, and that is sound — it is free, it is searchable, and it covers cats and dogs separately. But the lists have a flaw that people run into immediately, and it is worth naming before you open one.

A list gives you one word, toxic, for two completely different outcomes. Tulips, daffodils, hyacinths, azaleas, chrysanthemums, cyclamen, oleander and rhododendrons are all on it. Some of those mean a sick afternoon. One of them means a dead cat in three days. Read like a ban list, it is unusable — there is too much on it, and it drives people either to panic or to give up. Read for what each entry actually does, it works.

The short version, if you want one to carry: bulbs are worth suspicion as a class, true lilies and daylilies are a category of their own, and roses, gerbera daisies, sunflowers, orchids, freesia and snapdragons are on the safe side and can be given without a conversation.

If you have a dog and no cat

Then most of this is not aimed at you, and there is no reason to be anxious about a vase of lilies. The renal poisoning is a cat problem.

Your hazards are a different list — bulbs, and the grapes-and-raisins question, where the honest position is that the toxic dose is unpredictable between individual dogs, so there is no safe number. The one thing worth taking from here is the first-aid correction, because it is the sort of thing people do at three in the morning from memory: hydrogen peroxide to make a dog sick is a real veterinary measure, at a real dose, on a vet’s instruction — and it burns the stomach lining, so it is not something to reach for unasked. Ring somebody first.

If it has already happened

Go now. That part is at the top of this page and it is the only urgent thing here.

Two things to hold while you go. The first is that early treatment works extremely well — the outcomes are good when the kidney readings are still normal at the point somebody starts, which is an argument for going before you are sure rather than after. The second is that the warning signs are close to useless as a trigger, because cats hide illness and the early stage of this is quiet. Do not wait to see something.

And if this has already happened to you and you are reading it afterwards: one person said the thing worth repeating, and it was aimed at whoever had sent the flowers. It is a common mistake, made by people being kind, about a fact the flowers do not come labelled with. Somebody else described the effect of finding it out as going straight off to check their own house. That is the useful response to knowing this, and it is available to you now in a way it was not an hour ago.