The career of electric speedster Aethero is over after the galloper bled for a second time during a barrier trial at Sha Tin on Tuesday morning.The five-year-old was having his first trial since February and hasnt raced since bleeding for the first time in the Group One Chairmans Sprint Prize in April last year.Its heart-wrenching, said trainer Caspar Fownes. He just had an easy trial, its incredible because weve scoped h