Lilies are extremely toxic to cats and pose a serious, often fatal risk. All parts of true lilies (genus Lilium) and daylilies (genus Hemerocallis)—including stems, leaves, flowers, pollen, and even the water in a vase—contain substances that can cause acute kidney failure in cats

. Ingesting even a small amount, such as a few petals, a bit of pollen while grooming, or drinking vase water, can lead to severe poisoning. Symptoms typically appear within 1 to 3 hours and include nausea, vomiting, drooling, lethargy, and loss of appetite. Kidney damage progresses rapidly, often becoming irreversible within 18 to 24 hours, leading to kidney failure and death within 3 days if untreated

. The exact toxin responsible is unknown, but it affects cats uniquely; dogs and other animals do not suffer the same kidney failure from lily ingestion, though dogs may experience mild stomach upset

. Because of the high toxicity and rapid progression, lily poisoning in cats is a veterinary emergency requiring immediate treatment

. In summary, lilies are highly toxic to cats, and even minimal exposure can be fatal. Cat owners should avoid having lilies in their homes or gardens to prevent accidental poisoning