8 mo. old bite small dog, help!!!

Question
QUESTION: We have an 8 month old German shepherd pup (has been spayed).  We got her at the age of 4 months, and she has been wonderful.  She is hard headed and feisty, but very good with everyone until the other day.  I wasn't there but from what I understand my Mother-in-law was sitting in a chair with her Dachshund in her lap. Some form of fight broke out between the dogs and our GSD grabbed the Dachshund by the neck and bit him hard.  It almost killed the little guy, but our GSD seemed to be confused as to why she was in trouble after it happened.  She has not been around any dogs since, but she hasn't shown any aggression at all.   The Dachshund tends to pick on our GSD and they get into tiffs sometimes, but never violent. Also, the GSD goes to the dog park often and plays very well with the other dogs.  We are now beginning to be frightened that she might do this again, or even to a person, but she is always so sweet I just don't know what to do. Is there someone we could take her to to have her temperment assessed?  
I would appreciate any help,
Brecht

ANSWER: I guess a private dog trainer or behaviorists migt be able to watch the interaction, and decide what is really going on.  See if y9our vet can recommend a good one.

---------- FOLLOW-UP ----------

QUESTION: Do you have any other advice, or anything?

Answer
Obedience training never hurts, but in this case, I don't think it will be enough.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm