Mine whines and wants to play with all dogs, but that is not an options or feasible. The only interactions he has had with other dogs has been at play time. Now, I take him places where he can see other dogs but he is not allowed to play with them. I increase the space between him and them to the point where he is not reacting to them. I click and treat whenever he looks at other dogs and looks away without reacting. Once he stops reacting, I cut the distance, and continue. I have been told (by a few trainers) this is the best way to control his unwanted behavior.