Hi NinaJD… Frustrating, I know! I had the same issue with a horse that I purchased last year. Seemed he always was getting cuts and bites all over him. He’s a 17h OTTB, and so overcoming all of his issues like this has taken longer than I expected. However, the thin-skin issue seemed to be one that had immediate improvement, and continues to improve, with just good nutrition. I began feeding Triple Crown Lite (highly supplemented feed) and have added supplements that have increased levels of amino acids (glutamine, lysine, arginine, etc.) and biotin. Within a couple of months, his skin improved tremendously, to the point where he wasn’t showing scratches or love bites from playing with the other horses. He also became more resilient in fighting fungus issues he used to get on his face and socks.