Is there any way to sell a horse other than through the selling/claiming races?

on the horse data screen there is a small 'A' in a round blue background and a box next to it. write in the box your asking price or 'reserve', then press the 'A' button, the horse will be entered at auction on that day after racing.

Be careful if you want to auction horse with no reserve just click the A button, this cannot be undone however so make sure its a horse you want to see the back of or else bid for it to buy it back

Great stuff - thanks very much. I'll try it out next session.