I have a 23 month old boerboel. We have raised him from a few month old pup. I have an almost 9 year old son who my dog has recently started snapping at. Today he got gim in the arm. My son feeds him, takes care of him and has always been around him. My son will just pet him now and he'll snap. He's done it 3 or 4 times now. My son opened his kennel the other day and he jumped and knocked my son down and barked and stood over him. The breeder thinks he's trying to assert dominance over my son. How can we correct this? I don't want to sell him but I don't want him to hurt my son of course.