I moved here about a year ago from Upstate, NY with my almost 3 yr female Bernese Mt Dog, Jess. I had a great trainer in NY and while he can't be replaced, I am looking for a trainer in FL. Things were great up until about 4 months ago when she began showing some signs of aggression (only to some dogs - although I haven't had her around any dogs since). I really need some help! I did have her thyroid tested and that was negative. I was hoping to show her, but that is out if I can't figure out what is causing her to act this way. Any recommendations?