The game is very old and this is not going to stop. People have strong heart to support and bet on the game.
Many football players die too they run like a horse. However the OP person seems to have a kind heart - he couldn't bear the pain. Be careful and stay away from these games.
I think cockfighting is much as old as horseracing and to some countries it already becomes a tradition or if when there are so called fiesta's, they always have a schedule for cockfighting but let's forget that this thread was for horse racing and this one >
https://bitcointalk.org/index.php?topic=5397318.0 is the thread for cockfighting.
There will be a problem if let say government instantly put a ban on those old games because people are attached to them already and they will always find a way to continue betting again. They might consider looking for alternatives online. It's rare to see a footballer die in the field and footballers are not being forced to play but they can always stop if they feel something bad.