While real Christmas trees are not poisonous to dogs, it's important to ensure that the tree is kept away from your pet as much as possible. Dogs can be tempted to chew on the needles and branches, which can lead to gastrointestinal upset, vomiting, diarrhea, and even choking. If you have a real Christmas tree, it's important to keep it away from your dog's reach, and to monitor them closely if they are around the tree. Additionally, dogs can also be sensitive to the sap from the tree, so it's best to keep them away from the tree altogether.