help, worried

Question
i have a 5yr old male doberman, he came to me at 8 weeks of age, i was a single mum with a 3yr old. two years later i meet my partner and we have been a big happy family (we have 2 other dogs aswell non dobe) 6 months ago my second child was born. my doberman has been weary of her since she came home and will try to avoid her. we were sitting on the couch today and the 6 month old was gently stroking him he growled                   . he was put out side and i have arranged for a trainer to come in and asses things. my heart is breaking he is my boy and it hurts to think he could hurt my child (which i cant risk) i have never seen this behavior in him before. help

Answer
I don't know what you mean by "trainer" but AVOID at ALL COST anyone with fake credentials!  Most dog trainers know NOTHING about aggression.  Your dog is demonstrating fear aggression toward your infant.  Given the fact that he accepted the first child, this is quite aberrant but might be related to something that occurred during, or shortly after, the newborn was brought into your home.  Under NO CIRCUMSTANCES should you allow this dog to interact with that baby!  There is absolutely no way I can ethically advise you, because I do not have the opportunity to evaluate the dog's temperament, ask the many questions necessary regarding the past six months, and observe the dog's body language while the infant is in the room with him.  This can most likely be repaired but you need a qualified behaviorist with REAL educational credentials.  Be VERY CAREFUL whom you allow to advise you in this situation.  Under NO circumstances should the dog be in any way punished, coerced, or physically forced to interact with that baby.  This requires a careful, thoughtful and highly experienced evaluation and a very carefully structured behavior modification protocol.  Find an actual behaviorist ASAP.  Forget the "trainer", most people who do dog training don't have the faintest clue about what's going on in your home.  I don't blame you one moment for wanting to protect your baby, this is the absolute mandate.  However, your dog is not 'bad' because he is afraid; he might simply not be able to coexist within your household.  You might begin to look for Doberman rescue in your area; be certain they are legitimate.  if you live in the USA, Dobes Unlimited is the club rescue organization for the Doberman Pinscher Club of America and they are excellent.