Are lilies really dangerous to cats? Yes, lilies are very toxic to cats and ingestion can cause severe illness and even death. Your cat can be affected even if they aren’t the type to bite plants – it’s enough for them to get some pollen on their coat or paws and clean themselves. The primary effect is on the kidneys, and the first symptoms will be seen from minutes to a few hours after ingestion. If you think your cat has ingested something from a lily, contact your veterinarian immediately. Emergency treatment can save your cat.