The Greater Swiss Mountain Dog is thought to have originated when the Romans crossed the Mastiff breed with the Swiss dogs of the region. This breed was used primarily for herding and guarding since the Middle Ages. Learn all about the Greater Swiss Mountain Dog and see if one could be a fit for you.
http://dogtime.com/dog-breeds/tibetan-mastiff This is a gorgeous dog but I would not want to be its pooper scooper for sure. One sold recently for 1.9 million in New York. He probably can afford to hire someone to clean after it.