My boxer is 5 yrs old. The first 3 years we lived in a rural home with a fenced yard & very little traffic. We moved in to a subdivision with a lot of traffic and he has now come at me growling and snapping and just pinned one of my neighbors to the ground out in the road while she was walking. He was never aggressive until we moved here. We no longer have a fence and when he gets away from me, he goes staright for any other humans he may see. He even snapped at a neighbors face while she was sitting in my home petting him. My husband is ready to have him put down, I don't think he needs to be. Any suggestions?