Lilies can cause acute kidney failure when eaten by a cat. All parts are poisonous--even just a nibble of the leaf or flower can result in kidney failure. If you see your cat consuming any part of a lily plant, take him immediately to your veterinarian for emergency treatment.
|Lily of the Valley|
Lily of the Valley, not a true lily, is dangerous for cats too, but in a different way. Convallaria majalis, causes vomiting, diarrhea, decreased heart rate, cardiac arrhythmia, and possibly even seizures, when ingested.
|Hemerocallis Happy Returns Daylily|
|Spunky spends a lot of time in the Garden|
I do know that some things like aspirin are fine for us to ingest but are poison for our cats. When it comes to our pets, like our children, we are responsible for their safety. When you are unsure, it is best to err on the side of caution. If your pet seems sick after eating one of your plants, take him to the vet immediately along with a sample of the plant or at least the plant name.