No, no, it seems to be a much better solution to murder it and waste the precious gift of life because of a disability.Umm, how many times have you seen a horse be given a chance to do something else?
You do realize that a horse not being able to walk is extremely painful? Why would you put the horse through that until it dies in a pool of its own misery instead of ending its suffering right there and then? And the hell do you mean, "hasn't been given a chance"? What do you want, a horse to become an accountant? Horses are used to pull plows, pull buggys, horse races, pets, there are wild horses and tamed horses, there are horses who can sprint and horses who can go long distances. What op is doing is right, the horse is old, suffering and not being able to enjoy anything it had in the past, anyone who thinks he should keep the horse alive just because "oh its immoral to take a life" is way worse then they think the other guy is.