I know it is an oldie (2015) and it is about a thoroughbred (but nobody looks in that thread) so I am recommending it here to anybody that can access Stan and watch it. It is not a Disney movie - it is a doco.
I am a little conflicted at the end but it is compulsive viewing. I am not sure that what seems a positive for racing, does not become an argument against, mostly because of the footage of one race

Here is a link to it on IMDB

https://www.imdb.com/title/tt4137902...dark%2520horse