Though they have a bad rap, poinsettia (Euphorbia pulcherrima) plants are only mildly toxic to cats and dogs.

Sources:

During the holidays, Poinsettias are a popular Christmas plant.

Mechanism of action:

The milky white sap found in poinsettias contains chemicals called diterpenoid euphorbol esters and saponin-like detergents. While poinsettias are commonly “hyped” as poisonous plants, they rarely are, and the poisoning is greatly exaggerated. Far more worrisome are the plants listed below!

Signs of poisoning:

Mild signs of vomiting, drooling, or rarely, diarrhea may be seen. If the milky sap is exposed to skin, dermal irritation (including redness, swelling, and itchiness) may develop. Rarely, eye exposure can result in a mild conjunctivitis (“pink eye” secondary to inflammation). Signs are self-limiting and generally don’t require medical treatment unless severe.

Antidote and treatment:

There is no antidote for poinsettia poisoning. That said, due to the low level of toxicity seen with poinsettia ingestion, medical treatment is rarely necessary unless clinical signs are severe.

Threat:

Minimal.

Other plants to worry about:

Far more worrisome are holiday bouquets containing lilies, holly or mistletoe. Even bouquets brought into the house by holiday guests should be thoroughly inspected, as lilies are the #1 flower often used by florists. Just one or two bites from a lily can result in severe acute kidney failure in cats – even the pollen is thought to be poisonous! Other yuletide pants such as holly berries, mistletoe, and rosemary can also be toxic to dogs and cats. When Christmas or English holly is ingested, it can result in severe gastrointestinal upset thanks to the spiny leaves and the potentially toxic substances (including saponins, methylxanthines, and cyanogens). If ingested, most dogs and cats lip smack, drool, and head shake excessively due to the mechanical injury from the spiny leaves. As for mistletoe, most of us hang it high enough so it’s out of reach of our dogs and cats – nevertheless, it can also be toxic if ingested. Thankfully, American mistletoe is less toxic than the European varieties of it. Mild signs of gastrointestinal irritation are seen, although if ingested in large amounts, collapse, hypotension, ataxia (walking drunk), seizures and death have also been reported.