Me neither; however, I have a working theory about Pit Bulls. Their jaws are better for chomping than, say the longer jaws of other Canids. But what sets them off?
Dogs, I've discovered, have kidney stones just like humans. When any dog is in pain from an injury, they will bite—and a kidney stone attack is painful, indeed.
Keeping an ample amount of water available for the dog is a necessity to prevent kidney stones. IMHO, most of these Pit Bull owners don't qualify as responsible owners who would maintain a permanent water supply for their Pit Bull.
It’s certainly a possibility to explain the pit bulls that suddenly turn.