Looks like they might need to add genetic testing to whatever drug testing regimen is (hopefully) implemented:
http://sports.yahoo.com/news/olympics--cloning-horses-is-the-new-frontier-for-the-equestrian-world.html
Truth be told TGJB and TGAB are clones proving the environmental influence on the genome. Listen carefully at the seminars at Saratoga.
I have a few tail hairs from Secretariat ... I keep hoping ...