Sport: Flit-Gun Hop

Twelve years ago the nation's race tracks cracked down on the widespread practice of "hopping" horses; into limbo went the old standbys, heroin and cocaine, which mandatory saliva and urine tests showed up crystal clear. Inventive horsemen—and few are short on imagination—promptly began a painstaking search for a magic hop that would leave no telltale evidence. Stories and jokes about new nasal sprays and rectally-administered stimulants soon became standard race track shop talk.

Last week, nasal sprays were no joke for Silent Tom Smith, the man who developed Seabiscuit and this year trained...