Puppy Behavior?

Question
Dear Dawn,

I have a 10 month old Sheperd puppy who I have had since he was about seven weeks. This is not my first Shepard but I have NEVER worked so hard with a dog.  He has had three rounds of obedience training, has a very healthy diet, has an hour outside run daily, excellent health care and lots of appropriate toys.  He has his own crate, which he occupies at night.  He nearly always goes in the car with me I make trips.  He has, in fact, made several long trips and done quite weil.
  My question, if it is only one question, is that, in spite of all this time and energy, there are moments when I despair of his ever being properly trained.  He still, in spite of extensive attempts at socialization, tries to attack other random dogs (usually the small or submissive ones) as well as children under the age of 12.  He still pulls and lunges (in spite of the use of a gentle leader on the short leash, and the freedom to be on a long leash for parts of his walks).  He can ALWAYS hear the "take it" command but rarely pays attention to commands which involve his doing something he doesn't like to do.  (Point: there is no problem with his hearing)
  In a word, he is what you might expect, self centered and demanding.  Because he turned and tried to bite the vet (at three months) it was suggested that I release him to adoption or to have him destroyed at that age.  I think that this was a bit excessive but, as Cesar Milan points out, there are no bad dogs, just bad trainers.
  I have read "helpful" advice until I'm blue.  I've been consistant, tough, and demanding myself but the behavior continues.  He does seem to respond better to my 24 y/o son and his male friends than he does to me, or perhaps this is just a different response.  I don't want him to behave out of fear but I do want him to behave.  
  I have studied some animal behavior in the past and I do understand the alpha struggle.  Aside from patience, making myself look as big as possible, and trying to lower my voice, what more is there to do?  
  Any advice you might have would be appreciated.

Answer
Hi Laurel,  First off I have several questions.  Yes there are bad dogs out there, most the time due to genetics especially if you have had them since 6-9 weeks of age.  Did you meet the parents?  Where did you get the dog from, private breeder, pet store etc.  Also, in the trainings you took, were any of them dominance type trainings?  It sounds like your son has been dominating him so he has responded to that.  Also the comments you made about looking big etc. That is also not necessarily good.  My big concern is the attempting to bite a vet at 3 months and already showing aggression towards children at such a young age.  That is very bad.  This is abnormal behavior for a dog of any type.  You do not want to see any aggression from a dog until at least a year of age as their mentality up until that time is equivalent to a human child.  You wouldn't want to see that type of aggression in a human child.  At 3 months of age his mental age equavilenacy to a human child is approx. 2-3 yrs old.  Imagine a 2-3 yr old attacking an adult.  What was happening at the vets that triggered this event?  He is now 10 months old, and his age equivalency is that of a 11-13 yr old human child, so you are now starting the teenage stage of a dog's life, which is the hardest stage of a dog's life and can last until they are a year and a half to two years old depending on the dog.  The aggression will probably not get better as this is the time in their life when the natural protective ability starts to come out anyway (around 12 months old).  The aggression towards other dogs is not that uncommon with shepherds and is the least of my worries in this situation.

Please answer my questions above and I might be able to help you get through this.  

Dawn