A surprising number of horses end up having to be rescued from the actions or inactions of their owners. Instead of seeking help some horse owners simply let the horses suffer from a lack of proper care and feeding.
And when owners can no longer properly care for their horses it is the responsibility of the horse owner to assure their horses end up in a viable situation. Horses can be sold, donated, leased, turned over to a rescue operation, or in some cases euthanized. Giving up a horse can be emotionally difficult and is the main reason horses end up in trouble. The first obligation is to the horse, not the owner.