Aggressive German Shepherd

Question
Our dog is a 5 y/o Black German Shepherd, approx. 85+ lbs. and has been showing a lot of aggression within the past 1-1 1/2 years.  We have a 3 y/o son at home and he has showed aggression to him and myself as well.  He is not really aggressive towards my husband.  He has nipped at my nephew (12 y/o) and my niece (20 y/o).  We now have to keep him blocked off in a separate room as the aggression is getting worse.  No one other than myself or husband can go near him. I do not allow my son near him as I am too fearful he will bite him.  We feel as if we are at a crossroad of what to do with our dog.  Is it too late to try obedience with him? Or is he too far gone we need to put him down? Despirate for the right answer.

Answer
No there is no reason to put this dog down at all. At the age that he began showing these symptoms he was reaching maturity,. These are highly intelligent working dogs and need to have a secure pack order and a job to do.. Walk your dog, twice a day briskly until he's tired. Don't allow him to pull in front of you or lag. Have him carry a pack. Get him toys that challenge his mind, kongs etc that hold treats he has to work to get to. Get him involved in obedience training NOW do not wait. Try to find a trainer who is familiar with the breed or who is familiar with at least working dogs. He/She can help you deal with this too. If he isn't neutered do so immediately. You're doing the right thing by not leaving him in an area that he could hurt someone, however it's also going to make things worse for him. Make sure at least twice per week he works/runs/plays until his tongue hangs out. Treadmills are wonderful.
Type Alpha Boot Camp into your browser and print out the information they offer. It is wonderful,. Find a trainer who KNOWS how to deal with alpha dogs and such situations. Your dog will be fine,. This is website.  http://www.sonic.net/~cdlcruz/GPCC/library/alpha.htm
Cindi