Your puppy was scared silly - not aggressive in the sense that vet indicated and no need for a behaviorist based on what you've told us. A dog will aggress and fight - even bite - when they are scared but at 13 weeks, he has no ability to actually want to attack something out of dominance or the desire to show his power over them, which is what a truly aggressive dog wants.
Your baby just doesn't want to get hurt and he likely sensed the vet was tense and reacted. Sounds as if he "read" her right. Choose another vet with a better knowledge of dogs and your baby will be much better off.
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |