The inside of that stable door looks to be a potential injury hazard for the horse unlucky enough to reside there. It's quite possible that it's front hoof could get trapped between the front and back layers of the door given that his got damage like this. I hope that this is acted upon quickly
Great trainer all the best, l was told about a long time ago by a gentleman named mr joe guest whos no longer with us.He was a racing man like me. Mr DO'C.