There's a really good book to read: https://www.amazon.com/Beyond-Track-Retraining-Thoroughbred-Racecourse/dp/1570764026/ref=pd_cp_14_1?ie=UTF8&refRID=JVCRHZHA34JRBEGE6MAD
I bought this when I decided to commit to buying my mare (OTTB turned broodmare turned jumper). A lot of it didn't apply to me because it had been 10+ years since she had been at the track, but still good to know.