In advance of this year’s Kentucky Derby, the new safety standards will be rolled out for the opening day of the Spring Meet in April. Winning horses will be routinely tested for the presence of more than performance-enhancing 100 drugs. Horses will no longer be shod with certain kinds of horseshoes. And owners will be required to keep older samples of horse blood and urine on hand for retrospective drug testing. In addition, the new rules require all jockeys to wear safety helmets and vests. Churchill Downs developed the new standards in consultation with veterinarians from the American Association of Equine Practitioners, among other groups.