Back problem plagues Tiznow American horse of the year Tiznow, having suffered a back problem in April, has been giving his connections fresh cause for concern.The Breeders` Cup Classic winner had refused to extend himself when stepped up to serious work.'When we started galloping him, he didn`t want to leave the pony. He doesn`t gallop like himself. He had trouble extending himself.' trainer Jay Robbins told The Bloodhorse. Connections had thought that the horse was suffering a recurrence of the problem of his vertebral column.However, a subsequent scan revealed that the root cause is more likely to reside in the lower back area.Robbins has decided to adopt a wait and see policy with Tiznow. He plans to confine the horse to a light exercise regime for the time being.