This giant, gorgeous dog was bred to be a guard dog and has strong territorial instincts. And the great Pyrenees defines his territory as "as far as his eye can see." He will run off if not contained by a fence or leash. These dogs were bred to think independently and to make decisions on their own, so if you are looking for an obedience champion who hangs on your every word, the Pyrenees probably isn't it. But they are good watchdogs and will bark to raise the alarm of someone on their turf.