My little rescue ship tzu has some social issues! When someone is at my house , that he isn't very familiar with, (for example my grown daughter who doesnt live at home) when it comes time to say goodbye to them, he runs after them as they are walking out while barking. He acts vicious. He is pretty much ok when he sees that someone is invited in but heaven forbid that person walk out of the room quickly or yell goodbye as they walk out. How do I handle this and why is he like this? What sort of behavior is this? All in can think of doing is putting him in hs crate when the goodbyes come about or putting him another room. I don't want to do this because I want him to learn to not act like this. Help?