My pig guy has dogos. They are essentially a cross between a great dane and a pitbull. We lost one to a pig when it took a tusk to the neck. Honestly I would take a pit over one, at least for pigs. They seem to be better at fighting because they are lower to the ground. Trust me a mountain lion would make mincemeat out of one or even two. I suspect the lion would avoid the fight but if cornered it would not pretty. A mountain lion is much stronger and has claws. It is not even close.