Seems like a good idea. I don't think my horse will ever develop these but it's good to know what to do. And I'm glad you actually gave advice for once the sores do develop instead of the usual, "go to a vet".
One of my horses may have this on only one of his front legs, his right one. I think maybe its because that's always the one that he gets up and down off of when he lays down. But it looks more like a callus, hmm.