4 Answers

Be the alpha dog yourself.

Good tips here  >http://shibashake.com/dog/the-dominant-dog-dealing-with-dominance-in-dogs

You have to show the dog who the dominant one is. Even something as simple as walking the dog and letting the dog be in front, confers a sense of domination, i.e., "the dog is walking YOU."

My son trained his American bulldog from a puppy to know he was the boss. Noticing the mama dog would growl and/or gently bite the puppies' necks to subdue them, my son copied the behavior.  Dieszal would immediately stop his play or aggressive behavior and "hit the dirt" belly up. He still acknowledges both six years later. He even stops if I growl at him during play, and my growl is poor.

Yes, how old is this dog?  If it is still under a year, it will be easier.  All who have responded are correct, you have to be the pack leader.  Pinch him and say no, when there is undesirable behavior.  Deny his food, until you are ready to feed him is another way of showing dominance.