You can read, right? The article states that the pit bulls ran up to the horses, not that they were barking at the horses from a fenced in yard. And, for what it is worth, IMO, pit bulls have indicted themselves by their own behavior - the papers are replete with stories of pit bull attacks. I witnesses a pit bull attack myself. A pit, off leash, at a family park attacked a Black Lab that was on leash and under control of it’s owner (unlike the pit whose owner didn’t have control). The Lab did nothing to provoke the pit. Are you aware that the Pit Bull was banned in England? And, for good reason too.
It used to be German Shepherds. Or Dobermans. Or rottweillers.