It may be that he has adopted the alpha role and is simply protecting his terriority, be it his home, yard, and even you, when going for walks, (yes you are a possesion in his mind). Showing aggressive behavior can be a sign that a dog has assumed the Alpha position, also.
You need to get back control of the authority, in every aspect of his life, and this behavior should taper off.
It is amazing what you think you have control of, but don't (in the eyes of a dog). There are a couple of threads on this forum that addresses these issue that you may be able to access in the search engine.
Hope that helps. |