Other dogs greet people by peeing on them. And, of course, there are others who are perfectly wonderful. Bad reactions at the door often lead to further incidents once the visitors are in the house. Dogs can become quite bold with so much food around, and there will certainly be ample opportunity for them to get into trouble on a holiday like Thanksgiving. You'll undoubtedly be too busy to supervise them effectively.
Little kids are often the victims of dog bites for a variety of reasons.
Some kids torment dogs, kicking, punching and pulling them. Others may just put their face right in the dog's face. And you can expect your holiday to be promptly ruined if anyone is bitten. So give your dog some extra exercise, a filling meal, and get him away from the chaos that will surely ensue. And have a very happy Thanksgiving.