The toxicity of both Poinsettia’s and Mistletoe have been highly over-rated. They both can cause a mild (usually self-limiting) upset stomach. Most cases can be managed at home. If you have any questions call your veterinarian or Pet Poison Helpline.
Here are 2 articles from Pet Poison Helpline:
http://www.petpoisonhelpline.com/poison/mistletoe/
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