He's back! Goliath was returned to the rescue as he has developed into a fear biter and has a bite record - one official and twice not recorded. He has been to obedience school and graduated. He has been worked with by three trainers. His behavior improved, but they could no longer trust him - and that works both ways. So, he's back.
Right now he lacks both trust and respect, but we are working on that. He has done well and had not tried to bite till yesterday when I was massaging him and started to rub and lift his front paw, as you would when the vet wants to draw blood, and he snapped at me. AH HA - now we have a clue as to what triggers the aggression. All of his visits to the hospital for his heart, all the IV's, etc. have made him fearful. He's also fearful of the other dogs in his area.
He is not adoptable with a bite record, and I certainly would not want him to hurt anyone in the future. I offered to adopt him and the rescue coordinator agreed. We have a lot of work to do. We are establishing respect and working on trust. My goal is to make him more brave and trusting and let him live out his life.