Many of you may have heard that lilies are poisonous to cats, and most of you with cats will avoid having these flowers in your house because of this – but what makes lilies toxic? And what happens if a cat does eat one?

Lilies are highly nephrotoxic to cats, meaning they cause damage to the kidneys. All parts of the plant are considered toxic, with the flower portion being the most toxic. Actual ingestion of the plant will lead to toxicosis, but even biting the plant or exposure to the pollen (rubbing on the plant and then grooming) can cause toxicosis.

Which lilies are toxic?

There are over 4075 known species in the lily family, Liliaceae, however not all will cause kidney damage in cats. These lilies are from the genera Lilium (true lilies) and Hemerocallis (day lilies).

What will you see?

Clinical signs of lily toxicosis include vomiting, decreased appetite, lethargy. On average, clinical signs may not appear until 12 hours after ingestion of the plant. This makes history very important – are there lilies in the home that the cat has access to? What type of lily is it? Kiendy failure can develop 36-72 hours after ingestion, causing increased urination and water intake. Severe cases can lead to tremors, stumbling and seizures.

What will we do?

Because of the high level of toxicity in the plant, any cat that could have had contact with one of these plants should be seen by a veterinarian. A full history and physical exam will be done. Treatment may depend on how long it has been since ingestion of the plant. If the cat is seen within 2 hours, it is possible to induce vomiting to get rid of any plant material in the stomach, and administer charcoal to absorb the toxins. This is of course the best case scenario, but cats are quite sneaky and may eat the plants without their owners knowledge so unfortunately many cats are not seen until they become sick. If it has been longer than 2 hours since ingestion, induction of vomiting is essentially pointless because everything will have been absorbed.

Bloodwork and urine testing is highly important in these cases – an elevation in kidney values as well as electrolyte abnormalities may be seen on bloodwork indicating kidney damage.

Any cat who has ingested lilies, regardless of bloodwork abnormalities, should be placed on IV fluids. This treatment may last 48-72 hours and is used to diurese, or ‘flush out’ the kidneys, to prevent or slow down kidney failure.

Symptomatic care is also implemented – controlling nausea, abdominal pain or seizures if present.

Daily bloodwork and urine rechecks are highly valuable, as they monitor kidney function to help gauge response to treatment.

What is the prognosis?

Prognosis may change over the treatment period, depending on response to treatment. If treatment is initiated within 18 hours of lily ingestion, and before onset of kidney failure, prognosis is considered good. Prognosis will decrease as kidney failure develops.

Though lilies are beautiful flowers to have around, their impact on the health of our cats is just not worth it. If you have plants in your house that you are concerned about, or don’t know if they are toxic to your pets, feel free to consult your veterinary team who would be happy to help you. Truth be told, most of us are not well versed in plant identification so it is most helpful when you can provide us with the name of the plant, and we can do the rest! The pet poison helpline website (https://www.petpoisonhelpline.com/) also has a great search section that can tell you what happens when a pet ingests a certain type of plant.

Written by Dr. Kristen Wilson
Learn more about Dr. Kristen Wilson here.