Fostering Idaho

A good 10 years ago in the Santa Anita paddock garden, former trainer Matt Chew was leading a stately old schoolmaster named Fred through and around an afternoon gathering of children with developmental issues when a diminutive figure from the crowd locked eyes with the horse. "I walked over and handed him the shank and said, 'here, take him. He's yours,'" says Chew about the curious soul, a 10-year-old named Austin, onto whom he foisted the docile Fred. "He starts walking around with the horse and he starts talking to...