"Alpha" has been used so much that it has lost most of its meaning. Strictly speaking, dominance means "priority access to a desired resource." There could be many reasons why your dog barked at another dog. Thor does that all the time, and he is definitely not an alpha dog.
What behavior specifically are you trying to change? Is he aggressive towards strange dogs? Too rough when he plays with friend doggies? Can you give us more info?
__________________ If you love something, set it free. Unless it's an angry tiger. |