I need help
We have a 15 month old intact male GSD. We started having issues with his aggression and training when he was about 9 months old. Up to that point, we took him to the dog park 2-3 times a week and he was always around people and places. Around 9 months old he became extremely aggressive to any dog and will bark at men when he is with me (I am female).
We got a dog trainer about 2 months ago because of the behavior. He knows all of the basic commands plus some. When he is in the house, he is fine. Outside of the house he has become a terror. We recently got an electric training collar at the advice of the trainer because no other corrections were working consistently.
The collar worked for a bit, but now he does not care. The other day he saw a bird and drug me across the ground (I am 130 lbs) and I almost lost grip. This was while pressing the remote for the collar. He would cry, but it did not stop him. He no longer does heel or stay for me out of the house. He seems to not care. I do not know what else to do. I am starting to become concerned for the safety of all the other dogs in our community (we live in a townhome and have mutual dog yards). I am also becoming concerned for myself. When he pulls me, I have been pulled down to the ground, fingers have become twisted and bent, etc. I am concerned he is going to pull me one day and I am going to break something and he is going to hurt another dog.
I love him, but am at the end of what I know to do. I feel as if we have done everything we were told to do. Feeding him after commands, NILIF, getting expert help...what else can we do?
A side note, Lux could have gone to a working home...the breeder almost kept him for a working dog. She said he could go to the right pet home, but I am starting to think maybe she was wrong about him being the right fit for an only pet home?