Originally Posted by ochre
Dogs are hunters; horses are prey. Raising them as pets and their inherent gentleness applies to their interactions with humans almost exclusively. Dogs primal drive is to take down animals such as mini-horses.
True, my beagle was always chasing our horses (the full sized-ones) nipping at their legs. She probably would've taken down one of those mini's...
But I bet if had been a german shepard or a lab, the question of how he was raising them would have never been asked.