I recently rescued a lost dog. He is believed to be 1 and half shih tzu/ poodle and not fixed. I already have 3 dogs in my household-all are fixed. 2 male shih tzu (father 6/son 2) and a female yorkie 3. The "new" dog is only trying to mount my older dog (6) and constantly licks him. We have had him for 3 months and this behavior just started. He plays with the other dog (son 2) but does not assert this behavior. He also pays no attention to the female. The 2 yr old boy is the biggest but the father 6 is the dominant one in of the 3. Obviously the new dog is confused? What is going on and how do I stop it?