I'm exhausted, I rode a horse all day without allowing it to rest.
That sounds really mean, why didn't you let the horse rest?
Horses don't need to rest, they like like to run. The horse was fine.
Riding a horse all day can be strenuous to the horse. You should give the horse a rest next time.
They're just animals, they're supposed to run. Who cares about the horse anyway.
Horses are fragile and they get tired too. Make sure you don't over work them because if the horse gets injured it could be very expensive for you to have the horse treated. I'm sure you would feel bad if something happened to your lovely horse.