Did you get Carl as a pup or an older dog? If he was over 8 weeks, he may have had a bad experience with a person that has a beard or wore a baseball cap. My Cera has an issue with older women, because she was beaten by a woman who cared for her a short while. That can be a great problem to address, but check with your vet. He may be able to recomend behavior therapy that can correct it, or atleaset control it.
Good Luck!
~~Mysticdoberman
Originally posted by Rottie:
I would like to do therapy work with Carl. But, there's some people he just doesn't like. We can't figure out why he doesn't like these people or if there is a common trait in these people that he doesn't like (i.e. men with beards, or wearing baseball caps).

I would really like to do therapy work with him, because he has a great personality for it, but I don't want anybody to be offended if he doesn't like them I just wish I could figure out WHY!