I'm looking after a rescue horse. Rescued last summer with the worst rain scald imaginable. Hair has grown back and skin is healed, and the horse has been rugged all winter. On the mild sunny days I take the rug off for a few hours for some fresh air, but as soon as I see clouds I put it back on. His coat is very soft, fine and fluffy, even on his neck where it's been exposed all winter. I can't imagine it has any waterproof quality to it at all. Is this just genetic or can anything be done to improve it? He is fed linseed oil. He lives out. I would have thought it unusual to have rain scald in the middle of the summer, so I assume his fine coat was a contributing factor. Are some horses just destined to be rugged all year round?