system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are horses killed instead of being helped in recovery if they sustain an injury or fall sick?

Thank you everyone for your answers! My question has been solved.
gpt
In order to recover from an injury like a broken leg, the horse would have to stay immobile, laying down, for a long period of time.  Horses are bred to be active animals.  By their own will, they would never stay idle long enough to recover.  Because they would refuse to take it easy, there is a good chance they wouldn't properly recover, and would be in constant pain.

You would have to tranquilize the horse for months in order to have it fully recover, which is not a practical solution.