Not typically, unless they have a very strong allergy to pine. Many people have dogs that live with them inside the home with a Christmas tree, and they don't have any problems with it. However, if your dog has a history of being sensitive to pine or other trees, it's best to take extra precautions when decorating your home for Christmas. If your dog does have a sensitivity to pine, you can try using an artificial tree instead of a real one. Artificial trees don't have any of the same allergens as a real tree, so they can be a safer option for your furry friend.