Our dogs usually share some of whatever we are eating, so they definitely get turkey, dressing and even a bite of pumpkin pie for Christmas (and of course, for Thanksgiving as well) ; but as far as getting them presents for Christmas, that is totally not happening.
Animals , dogs especially, enjoy being a part of the family celebrations, and I like to keep them included as much as possible. However, even if they undertstood about Christmas and presents (which they don't), they would still just want the turkey, and not a new doggie toy.
I think this is somethingthat each family has to decide. If people enjoy buying presents for their pets; then by all means, let them have their fun and buy presents; but it is not something that is going to matter to your dog or cat whether hegets a Christmas present or not.