My old springer spaniel. Augie was a very gentle fellow. One day I stopped at a friends house for a second, he had a man doing yardwork for him. All of a sudden we hear Augie barking and the man is yelling "get this viscious animal off me", well, Augie has him pinned against the garage and won't let him move. I took my dog and left. A couple days later my friend calls to say he caught the man stealing from his home. I think our four legged friends sense things about people. My dog got along with everyone except that guy. My advice, don't trust anyone your dog doesn't trust....tom