This popular holiday plant accounts for the majority of plant calls to Pet Poison Helplines during the holidays. Although they have a bad reputation, the relative toxicity of poinsettia plants (Euphorbia pulcherrim) has been exaggerated. The most dangerous part of the plant is saponin-based irritants found in the milky white sap. As the plant is chewed and sap ingested, mild oral/dermal irritation, salivation, vomiting, and diarrhea may result. A majority of the cases can be managed at home.
Since there are many varieties of this plant grown worldwide the common name of “mistletoe” can be misleading. The variety under which ‘couples stop to kiss’, is the American Christmas mistletoe, Phoradendron tomentosum. Like the poinsettia, this plant gets a bad rap. Rumors of its toxic nature are largely attributed to its cousin, European mistletoe, Viscum spp. Although ingestion of American mistletoe leaves, berries or extracts may cause mild stomach upset, serious or life-threatening poisoning (hypotension, collapse, ataxia, seizures) are extremely rare and are not expected following most exposures in pets.
Prized for its evergreen color and bright red berries, the Christmas or English holly, ilex aquifolium, is similar to the Mistletoe as another overrated toxic plant. The problems caused by holly ingestion are two-fold. First, the spiny and leathery leaves can result in mechanical damage and, potentially, a foreign body obstruction of the gastrointestinal tract. Second, the leaves and berries contain saponins, chemicals that have a detergent-like effect on tissue and result in gastrointestinal irritation. Most holly ingestions can be managed at home.
Recently, florists have started to use Japanese Yew to make holiday wreaths. Yew is a vibrant evergreen shrub that is commonly used in landscaping. This plant, dubbed “the tree of death” contains potent taxines. Every part of the plant is considered very poisonous. If ingested, cats and dogs can show one or more of these symptoms: Drooling, vomiting, difficulty breathing, changes in heart rate and blood pressure, weakness, seizures, tremors, dilated pupils, coma and even death. The minimum lethal dose in dogs is 2.3 grams leaves/kg body weight. Horses and livestock are also at risk for poisoning which most often occurs when yew wreaths are used to decorate stables or trimmings or discarded wreaths are thrown into pastures or dry lots.