[chico2]

I don't know much about agression in a dog,but I suppose he had his reasons.
I've learned a lot being on this board and it takes a lot more than just loving to be a puppy-owner.
I don't doubt that you cared about him,you are probably lacking experience with puppies.
I am hoping the people who get him can take him for obedience-classes and will be able to spend more time with him than you were and I do feel sorry for both you and your puppy,I could not imagine giving any of my cats to anyone else....Hopefully you'll keep in contact with the new owners and tell them about the problem you had,so they are prepared to deal with it in a good way.
I met a prime example of a GS pup(7 month) yesterday having finished the first course in obedience training,an absolutely amazing puppy.