Shoe Stretch Spray Please Help, I've Never Hear Of This Before?

Please help, I've never hear of this before? - shoe stretch spray

I have an 8yo TB and latley when they returned from one of our walks, just below the ball is still scratched and bleeding. This happens only once in the foot. No shoes, and I do not know what the cause, and I do not know how to correct it. Gather all the grass and the earth, but there is a patch of rocks (we go on a river). There is a long stretch of deep sand, that we are also at a gallop. Someone said that it can rely on their hind legs and can achieve a reduction in the rocks.
I have tried to put the boots to him, Bell, but that does not work. I've started, you think, if wrapped her legs, as in dressage, but also in the joints? l really do not know what to do.
It's never lame, and when we come back, I've always cleaned his wounds and put cetrigen aerosol. But I feel so terrible that it was bleeding still, when we got home!

What should I do? If that happens is someone else?