Lilies known to cause kidney failure in cats include the  Easter Lily, Tiger Lily, Oriental Lily, Asian Lily, Daylily, Stargazer Lily

With the return of spring, comes celebration. For Christians, Easter is a time of rejoicing. For people everywhere in the northern hemisphere, spring signifies renewal, a fresh start. New green growth and blooming flowers mark a new beginning. Many people will celebrate during this time by adorning their households with flowers and plants. However, cat owners need to know that some of the most common plants are highly toxic to their beloved feline companions.

Easter lilies (Lilium Iongiflorum), other species of the genus Lilium (Tiger lily, rubrum lily, Japanese show lily, Asiatic hybrid lily), some species of daylilies (Hemerocallis spp), and possibly other species of the family Liliaceae are highly toxic to cats. Ingestion can lead to kidney damage. All parts of the plant are considered toxic, and intoxication can occur with ingestion of less than one leaf. To date, the toxic component has not been determined.

Within the first two to six hours of lily ingestion, a cat might manifest intestinal upset, including vomiting, loss of appetite, and depression. Signs might temporarily subside only to return within twelve to eighteen hours as kidney damage ensues. Treatment consists of rapid decontamination (inducing vomiting to remove plant material, administering activated charcoal) and intravenous fluids. Postponing treatment for more than eighteen hours can result in renal failure and death. Therefore, prompt and aggressive veterinary care is paramount. With prompt treatment, full recovery is possible. However, if treatment is delayed, varying degrees of permanent kidney damage will occur. If the cat is not treated at all, death usually occurs in three to seven days.

Cats can be extremely inquisitive and might graze on plants in and around a house.  Therefore, cat owners are encouraged to avoid placing lilies where cats reside, whether indoor or outdoor. During Easter celebration (and for that matter year-round), substituting Easter lilies and other kidney toxic plants with plants such as Easter orchids, Easter lily cactus, Easter daisy, or violets is recommended.

To see additional photographs of lily plants, visit this page on the Cat Fanciers Association website: Lily - dangers.

References
Volmer, PA (1999). Easter lily toxicosis in cats. Veterinary Medicine 94: 331.

Volmer, PA (2003). How dangerous are winter and spring plants to pets? Veterinary Medicine 97: 879-893.