Lily Toxicity in the Cat

Lilies are commonly kept flowering ornamental plants that are used in holiday celebrations, weddings, and funerals, and in various floral arrangements. Lilies of genera Lilium and Hemerocallis (day lilies) have been shown to cause nephrotoxicity in cats. Confusion arises because so many different plants are called lilies. Members of the genus Convallaria (lily of the valley), while sparing on the kidneys, elicit toxic effects because they possess potent cardiac glycosides similar to digitalis. Even more confusing as to which lilies are toxic is the fact that many hybrids exist. The majority of the public do not know that lilies can be dangerous to cats and, in fact, cannot correctly identify the plants in their own homes. Cats have been shown to be extremely sensitive to the toxic effects of lilies. As little as 2 leaves or part of a single flower have resulted in deaths. It should be pointed out that the whole plant—petals, stamen, leaves, and pollen are toxic. The exact toxic dose and the precise toxins responsible for renal damage are currently unknown. The quick onset of clinical signs suggests a rapid absorption rate of the toxin. The renal tubular epithelium appears to be the target of the toxin. Studies indicate that it is the water-soluble fraction of the lily that is nephrotoxic. In cats, clinical signs of lily intoxication include salivation, vomiting, anorexia, and depression. Polyuric renal failure leads to dehydration and anuric renal failure and death results. No analytic verification of lily ingestion is currently available. Successful treatment includes initiation of fluid diuresis before the onset of anuric renal failure. Once anuria develops, peritoneal dialysis or hemodialysis is the only potential treatment. Differential diagnoses of lily poisoning include any potential cause of acute renal failure in a cat. Prognosis is excellent if fluid diuresis is started before anuric renal failure has developed. The public must be made aware of potentially toxic ornamental house plants.