This time of year the poinsettia is a commonly encountered house plant. The sap of this species contains irritating chemicals that induce hypersalivation, vomiting, and diarrhea. Leaves and stems are the most likely to produce clinical signs. Several plant species can cause life threatening poisoning if ingested. The Easter lily and its relatives are known to cause severe kidney failure in cats if ingested.
Landscape plants can also be very toxic.
The azalea and rhododendron shrubs contain potent toxins in all parts of the plant. They can cause gastrointestinal disturbances, convulsions, and death. Ingestion of any portion of these common shrubs is an emergency condition. So too is consumption of any part of the oleander shrub. The toxic principles in this plant interfere with cardiac function, and can be deadly.