Hello! My first post here. Shooter is 2.5 years and for the past 2.5 years he has been excellent with strangers and other dogs. Suddenly he seems to be extremely territorial in the yard, barks at other dogs and people walking by. He got out of the house the other day as we were going out and started to jump and bark at a pedestrian. We're very worried about this new behavior. We're thinking it's maybe he's being overly protective. When I used to walk him there was a dog that used to come very aggressively from a certain yard and tried to attack me once so i'm thinking he's doing it to protect us? Any ideas as to how we should go about this? 

A good bark collar will shut it down. I recomend TT.