Winston first showed signs of Seasonal Flank Alopecia just before his second birthday. Its occurs every year starting around the beginning of spring. For Winston, his hair always grows back in, but his is not always the case for all dogs. This may be determined by how quickly its treated. I do use Melatonin (3mg) and vitamin D3 (before bed time) and it seems to help better than any other meds or supplements I have tried.