When your dog isn’t behaving the way you want, it’s important to correct, and not punish him. You may think you’re giving him a “time out,” but all he knows is that you made him sit in the corner for five minutes. Unlike a child, they don’t connect the “punishment” to the bad behavior. When you correct a dog, you immediately alert them that what they’re doing is wrong and then you show them an alternate, acceptable behavior. Dogs live in the now! They understand the most immediate cause and effect. And there is no better situation to correct your dog than when they are showing signs of being territorial.
If your dog is acting territorial, it is likely that they were never given rules, boundaries, or limitations. When you move into a new home, you should show your dog which areas he is allowed into and which ones he isn’t. Take your dog for a good long walk, and then enter the house, walking him through the rooms where it is okay for him to be. For the rooms where the dog is not allowed, you should claim the doorway or entrance. Show him that that room belongs to you. Don’t allow him in, and stay there until he backs away. Then he will see, “This is a room I shouldn’t go in.” If you set these rules, boundaries, and limitations in the very beginning, and reinforce them every day, the dog will obey. If the dog tests the boundaries, just deliver a quick correction and show the dog what you want.