First I'm sure you've watch television and caught a wild life show or two. Have you ever seen a pack of lets say lions. In that pack, there has to be a top lion. We all know it's the large males. Someone has to be in charge.
Someone has to make the decisions.
Dog packs work the same way. It's this one crucial point that fails most dog owners. If you would take the time to establish with your dog, who is on top, there wouldn't be a single problem you could fix with your dog. If your dog doesn't respect you, it won't listen to you. I specialize in behavior modification.