I have an 8-yr-old GSD who bites people. I bought an Innotek Shock Collar but am not sure if I'm using it properly. I heard I should not use it to control aggression?

Cindy,

I have an 8 year old GSD who I can no longer socialize with any new people or animals. He had good basic training, grew up in our sub-rural property and was always friendly. He was the dog who broke down stereotypes about GSDs. The exception was towards the young boy across the street who was afraid of him. When I foolishly did try to introduce him I was shocked when my dog "nipped" the top of his hand (I shouldn't have been). Five years, one divorce and two house moves later...I'm afraid my GSD is less secure. He seems happy in my new home over the past two years but I'm now in a suburban neighborhood and I cannot have a fence. From inside, he often barks or growls at passing bikes, people and dogs. He got away and bit a neighbor when my father had him outside and on a leash. Another time he nipped a new puppy's fur that my boyfriend tried to introduce to him. I barely kept him from biting a woman when my son opened the front door prematurely. After each instance he retreats immediately and looks guilty and sad. He knows the "leave it" command and is always well behaved when I take him for walks. But sometimes he will whimper when I'm forcing him to "leave it" as the dog and owner on the other side of the street (or passing bike) goes by. My boyfriend and I are only ones that handle him now. I did buy an Innotek shock collar some time ago, but want to make sure I am implementing any training with it properly and have been told it shouldn't be use to try to control aggression? My vet indicated that older GSDs can become more protective. I'm simply convinced that the instability in our household has brought us here. At any rate I'm looking for whatever advice you can give to help me understand what if anything I should do to correct this, or keep from getting worse. If he is "ruined" socially, than I at least want to be sure that I'm doing the right thing by being resolute in not introducing him to any new people or animals.

Thank you, Sandy