forces at 500psi, higher than pit bulls, Rottweilers, German Shepherds and others you typically would think of first. Only breeds higher are mostly breeds you've never heard of. I was going to say, if a Pyrenees is raised with sheep or chickens, and if a pit bull were to attack its flock, my money would unquestionably be on the Pyrenees. But I have never seen one get even close to get aggressive with a person. We have 4 Pyrenees, but we got a German Shephard for protection.