The 152nd edition of the Kentucky Derby will be run with 19 horses instead of the maximum 20 after a late scratch less than 12 hours before the race.

Mage's team at the Preakness has settled into a stable routine at the Preakness after the horse's Kentucky Derby victory capped off a tumultuous stretch at Churchill Downs.

Two more horses died in the hours before 15-1 shot Mage won the Kentucky Derby by a length, making it seven in all and casting a shadow over the 149th edition of the world's most famous race.