Poisonous Plant Hazards

Almost any wild or cultivated plant can cause stomach upset in dogs and cats when a large enough volume is consumed. However, many plants can produce far more serious signs and can even be deadly.


Many cat owners are now aware that true lilies (Lilium genus- including Asiatic, tiger, Easter, stargazer, rubrum and red lilies) and daylilies (Hemerocallis genus) are very toxic to cats when ingested. All parts of the lily plant are poisonous to cats, but the flowers are the most toxic. Lily toxicosis usually causes acute kidney failure within 12-36 hours and death within 3-5 days. It is still not known exactly how lily ingestion causes kidney failure, or why it occurs only in cats and not in other species.

Cats who are treated quickly and aggressively within a short time of exposure have a good chance of survival. If the ingestion occurs within a few hours and signs are not yet observed, a veterinarian can induce vomiting and hopefully prevent absorption of some or all of the toxin. Vomiting should never be induced at home in cats. Hospitalization, intravenous fluid therapy, and supportive care are usually also required.


The sap of this ornamental plant contains a compound that is very toxic to the heart. The toxin is a cardiac glycoside that affects dogs, cats, and humans. Even a small amount can cause cardiac arrhythmias and death. It is not recommended to have this plant on the property where pets or children reside. Other plants that contain cardiac toxins include kalanchoe (mission bells), lily of the valley, yew, and foxglove. Yew more commonly causes severe gastrointestinal irritation and neurological signs such as seizures in dogs and cats.

Autumn crocus

This type of crocus has extremely toxic seeds and bulbs. The toxin targets rapidly dividing cells, leading to severe gastrointestinal damage and bone marrow suppression.

Castor bean

The castor bean plant's seeds contain a very potent toxin called ricin. The degree of toxicity depends on whether the bean (seed) is chewed and to what degree. Severe gastrointestinal signs, seizures, blood clotting issues, and multi-organ failure are possible.


Common plants that can cause significant vomiting and diarrhea include — rhododendron, cyclamen, amaryllis, chrysanthemum, and daffodils. The bulbs of daffodils are the most toxic, and consumption can result in depression and heart issues. Amaryllis bulbs can cause low blood pressure, tremors, and seizures. Gastrointestinal upset can also occur when pets ingest tulip bulbs.

It is helpful to make sure you know all of the common names of the plants in your yard and house and keep them recorded in your pet’s file in case of ingestion. It can help your veterinarian determine a possible cause for non-specific clinical signs. If in doubt about the toxicity of a particular plant, the American Society for the Prevention of Cruelty to Animals (ASPCA) website has helpful resources about poisonous plants.

If you have any questions about toxic plants in your home, please give us a call at 613-544-7387.

Written by: Dr. Edwards, DVM