no contract ? Those horses are his. You have no more right to them than you do the horses in my pasture. Call him, be friendly ask if you can have them back, as in ASK, ask nicely. If he balks ask bare bones what he would sell them back to you for so he could get some of his expenses back. Sure in reality he probably doesnt deserve anythign but if a couple hundred bucks can get em back. He might say sure. If you start demanding or using words like MY Horse, and MY Husbands horse, or show up with the police, Id tell you and the police to get bent and carry your happy hindquarters off my property. I don't know about SC law but in some states it is perfectly legal to shoot someone coming on to your property and taking a horse.
Just goes to show you went and entered into a very complicated contract complete with financing terms and it didnt occur to you to write any of this down ?