He is now three years old and I have had him for 15 months. He went to training classes but had to stop because he was too aggressive towards the other dogs. He pulls on a lead despite me having tried loads of different aids and now I have a badly injured shoulder. I previously had a Dobe with issues and sorted him out so I am not a novice at training but nothing works with this one. He is so stressed the moment I open the door to go out - he has learned to wait until I go first but I just cant stop him pulling and trying to attack any dog he sees.