My horse was diagnosed with nodular necrobiosis on his back (caused by an ill fitting saddle). They are little hard lumps under the hair, and in my boy's case- are very painful. He is on a course of Preddy Granules to make them go away (seems to be working so far), but I was just wondering if anyone else has had any experiences with them? IE how bad was it? What treatment did you use? Did they return?