Keep us posted as it turns out; I admire your willingness to deal with your friend to get this problem solved. We've got a pit mix (rescued as a pup from the pound; didn't know he was a pit till the vet said he was pit/shepherd). He's a cool dog, lots of energy and loyal. But I know that from his breeding if he ever got into it with another male, there'd be no stopping him. We sure haven't trained him to be that way; pits will fight like a German Shepherd will try to herd anything it can. The thing is to control your dog, whatever it is. Again, you've been upfront with your friend, and not tried to be all sneaky about resolving this. Way to be.
