Split personality Boston Terrier?

by Rhonda Heginbotham
(Vermilion, Ohio USA)

I have a 6 month old female boston whom I purchased at 8 weeks of age. She has absolutely been a joy to me and has taken well to both my 12 year old collie and cat, although she dominates them both. She was extremely easy to potty train and teach basic tricks such as sitting and staying. We have just completed a basic obedience course with an agility course attached, one other dog in the class. I have gotten past her chewing and have tried to curtail her dominating behaviors, however just recently she has begun to growl and snap and other dogs. This is very confusing to me, not to mention scary. This is not the same personality that I thought she had previously. All snapping situations were when I feel she felt threatened, but even if that is the case how do I correct her behavior? I cannot allow her to snap and growl whenever she pleases. Lately she has been doing it to my laid back collie when it comes to dog bones, treats, and lately I think me? My current trainer says I should grab her by her neck and tell her no, which I have done but she still continues this habit. Last night she did it to my other dog, I grabbed her neck and put her in the garage for a few minutes (separate from rest of family). This is my first boston and I have to say I love the breed up until this point. What should I do? I don't want to give up on Sophie at this point.

Rhonda Heginbotham