The common term "lily" is applied to a wide range of plants, but from a botanical perspective, true lilies belong to the genus Lilium (e.g., Easter lilies, Asiatic lilies, Tiger lilies) and the genus Hemerocallis (Daylilies). It is these specific genera that contain the potent, water-soluble toxins that are acutely toxic to cats. It is crucial to distinguish these from plants with "lily" in their common name that are not true lilies, such as Peace Lilies (Spathiphyllum spp.), which contain irritating calcium oxalate crystals but are not associated with the same rapid, fatal kidney failure.
The exact toxin has not been singularly identified but is known to be present in all parts of the lily plant—petals, leaves, stamens, pistils, and even the pollen. The toxin is highly water-soluble. When a cat ingests any part of the plant, the toxins are rapidly absorbed from the gastrointestinal tract. The primary target organ is the kidney. The toxin causes severe, irreversible damage to the renal tubular epithelial cells, leading to acute tubular necrosis. This damage disrupts the kidney's ability to concentrate urine and perform its essential filtration function, resulting in acute kidney injury and, without prompt intervention, complete renal failure and death.
There is no safe part of a true lily for a cat. The entire plant is considered toxic. This includes:
- The leaves and stems, which are often chewed on.
- The colorful petals.
- The stamens, which hold the pollen.
- The pollen itself. A significant risk occurs when pollen dusts a cat's fur; the cat then groses itself and ingests the toxin. Even drinking water from a vase containing cut lilies can lead to poisoning, as the toxins leach into the water.
To ensure safety, it is important to identify plants from the genera Lilium and Hemerocallis. True Lilium plants grow from bulbs and typically have large, prominent, often trumpet-shaped flowers with six tepals (petals). They have long, lance-shaped leaves arranged in whorls or spirals around the stem. Hemerocallis (Daylilies) grow from tuberous roots and have grass-like leaves in a clumping formation. Their flowers last for only one day but are produced in succession on tall scapes. If you are unsure of a plant's identity, it is safest to assume it is toxic and keep it completely away from cats.
