Many modern horses have easily upset digestion; which can indeed be a serious medical issue. A horse raised with or adapted to a more varied diet will be a bit

Many modern horses have easily upset digestion; which can indeed be a serious medical issue. A horse raised with or adapted to a more varied diet will be a bit more robust. I've known a horse that was fond of sausage and stripped fruit trees and blackberry bushes at every opportunity, her digestive distress after those episodes was never that serious for her. Bystanders may have suffered some.