Does a horse have to be put down every single race?

Answer 1

If by "put down" you mean euthanize, No, the majority of races are run with no loss of life to the horse. It is a rare instance that a hose suffers a catastrophic injury resulting in them having to be put down.

Answer 2

Horses are used to race everywhere every day. But the most common horse race is The Grand National. It is held in Liverpool, England, and people bet on the horses to win money.