Blood cells of a horse

I learnt from an article of one ex-trainer who told us that trainers are used to extract the blood of a horse to vertify if she is in a good condition (form) before they place bets on
her.  Sometimes, through tough training, as a normal horse fan, he can't tell if the
training has already raised the form of a horse  ready to win the race unless  a horse's red blood cells are increased and white blood cells are eliminated. HKJC has never published such information to all horse fans. Do any brothers have more information on this area?

玩到咁科學，非圈內人仕不可，
有態不代表必勝，
理論上有態必在表面，有質才難預知，
狀態方面Seabear一流水準，
去馬睇飛必屬rucrazy強項。