Originally Posted by RD
How about a livestock guardian like a Pyrenees? They're not extremely high energy dogs (the adults that I know are laid back, but still respond quickly to a potential threat) but they're naturally quite protective and working-bred Pyrs don't need to be trained to do so - though obedience training to keep them under control is a MUST.
But either way, getting the dog will be the smallest part of the equation - the big deal will be you and your dad learning how to handle the dog.
That is what i was thinking too RD. Walker my dog is a mix from a sheltar but because one of the breeds is a livestock guardian (Anatolia Shepard) he is protective when he needs to be and downright the biggest marshmallow when he and I are relaxed and not threatened. But it takes alot to push him to bite. He was relativly easy to train adn doesnt require alot of excercise either. Another thought if you dont mind hair and drool is a St. Bernard. Ours is the biggest baby and i mean BABY. She pushes people over to be petted but when two rotties came charging my mom she was not going to let them by. Her protective instincts were on all the way. Plus her bark alone scares people on the road