(((((VTGirl)))) I'm so sorry. I had a shepherd mix bite my child -- lightly --when he was four and it absolutely freaked me out. When I questioned my son further I realized that he'd been jumping over my poor dog -- length wise -- upsetting her.
She never bit him again. It was a one time thing. But much earlier -- years earlier -- the same shepherd mix lightly bit my sister (who is a serious royal pain). I cannot tell you how on target my dog was to realize that my sister is not right in the head.
Those were the only two times with my girl and she was an AWESOME dog. Absolutely awesome. I guess that's my way of saying that maybe to the dog it made a ton of sense.
I'm really sorry though -- it's so hard to go through.