Wagtail
Horse servant
I think some people are looking at things with rose tinted glasses, which in the case of blood banks is easy as visits are not allowed and you rarely get to know what happens to the horse. Still you can send your horse away, get a few hundred pounds and imagine he has a happy ever after life !
I have been there, and have never seen such large numbers of happy horses. You don't get a penny. When they come in in the winter they still have outdoor areas as well as the barns. They are very clean, and groomed and trimmed regularly. All the horses I saw were shiny and had neat manes and tails. They were in massive fields as far as the eye could see. Horses that would not be suitable are those who can't be on grass, or who don't mix well with others, or dislike vets.