[FirstYorkie]

I think it's important in these situations to differentiate between a dog who is lunging and barking and a dog who is truly acting aggressive.

The former may be saying "I'm excited. I want to meet this dog." Or, "Danger, danger! I'm going to protect us, Mom" or "Hey you big Oaf. Stay away from me; I may get ugly if I feel threatened." There really is nothing wrong with one dog telling another that he won't tolerate the dog getting close to him (provided the other dog has the sense to back away at that time or his owner has the sense to get him away).

In these instances, the dog is feeling threatened and yelling at him or otherwise disciplining him will only make him feel more threatened. Instead, place yourself between your dog and the other and project your confidence that YOU are in control of the situation. If he's saying he doesn't want the other dog to come any closer, respect that.

On the other hand, a dog who is lunging, snarling, and snapping at another dog who has not entered "his space" is another matter. This is a dog who may be looking for a fight rather than trying to avoid one. This situation warrants help from a professional. It's way beyond the scope of this board.