Looking for some guidance. I have an 8 month male GSP that i just got a week ago. Whenever someone other than family goes to pet him he snaps at them. They can be sitting down and he can lay right next to them and as soon as they touch him he tries to bite them. Does anyone know the best  way to correct this. I have had other GSP's and this is a first for me where they did not like anyone touching them.