Lilies and cats: the vase water and pollen are toxic too, and waiting until morning can be too late
I knew lilies were bad for cats in the vague way everyone sort of knows it. Then I actually read through what the FDA and Purdue's vet school say about it and realized I had about half of it wrong. Here's the rest.
It's not just chewing the flowers. The whole plant is toxic, stem, leaves, petals, pollen, and the water in the vase. Purdue's wording is that licking a few pollen grains off their fur while grooming, or drinking the vase water, can be enough to cause fatal kidney failure in under three days. Think about where a cat's face goes when there's a fresh bouquet on the counter. Yeah.
"Lily" also covers a bunch of plants that aren't the same problem at all. The kidney failure ones are true lilies and daylilies, so Easter, Stargazer, Tiger, Asiatic, Oriental, and the orange daylilies a lot of people have growing in the yard. Peace lilies and calla lilies aren't actually lilies. They irritate the mouth and cause drooling, which is unpleasant but a different thing. Lily of the valley isn't a true lily either, and that one's its own emergency because it affects the heart. So "is my lily safe" really depends on which one you've got.
This one surprised me. It's basically a cat-only problem. Dogs that eat lilies can get an upset stomach but they don't get the kidney failure, and per Purdue the actual toxin still hasn't been identified. So if you grew up with dogs and lilies in the house and nothing ever happened, that's why, and it doesn't carry over to a cat.
The timing is what I'd want everyone to remember. Early signs are vague. Quieter than usual, drooling, throwing up, not eating, anywhere from minutes to about 12 hours after. Around 12 to 24 hours in you can see more peeing and dehydration as the kidneys get hit. And the FDA says if treatment is delayed 18 hours or more, the cat will generally have irreversible kidney failure.
Which means the normal instinct, she threw up once, let's see how she is tomorrow, is exactly the wrong move here. With most things that's reasonable. With lilies the waiting is what does the damage.
If you even suspect it, call your vet or a pet poison line right away, and take the plant or a photo of it so they can tell which kind it is. Early treatment makes a huge difference.
Also, apparently cats that have never shown any interest in plants can just start one day, so "she ignores the flowers" isn't really protection. The vets' advice is pretty much if you have a cat, don't bring true lilies into the house at all.