My 9yr old mare paint has the weird wrinkles on both of her upper shoulder areas. They are firm wrinkles, not soft or loose. They do have some minor scabbing on the ridges, but nothing major. She does itch at them occasionally, but she seems to itch everywhere during these summer months. I've only had her since June but these waves in her skin have been the exact same the entire time I have had her. They don't bother her, aren't warm or anything so I figured I would try on here before spending the money on taking her to the vet since it is nothing major at all. The fact that is has been the same since she's been at her old place to where she is now makes me think it is not an allergy to food or fly spray. And I don't think it has to do with sunlight exposure since it is worse on her brown patches and much less noticeable on her other side, where is it on some white patches (same area at the shoulder). I attached a photo. Please help, any ideas at all?
Mystery Wrinkles on Mares Shoulders 
