Stiffler, my best friend's QH, has developed a strange gold spot on his shoulder. He has had no injuries to this area, and the spot was not there over the winter, nor do I remember him having it last year. He hasn't gotten a rubbed spot in that area, the skin seems normal, the mis-colored coat there is healthy and shiny. I can't quite figure out where this has come from. We have not applied any mtg or anything that could accelerate sun bleaching or anything on him. He just has a randomly gold shoulder. Note, the area very specifically is gold, not white or cream hairs like a scar. He also appears to have a second goldish area starting to show through below the first one.
He is registered as a bay, though I don't believe that is accurate for him (guessing probably brown?). He is out of a palomino stallion and a dun mare.
Picture of shoulder spot:
Otherwise a solidly marked horse, nothing unusual about his coat/color:
Picture of Stiffler coming out of his winter coat just a few months ago - clearly no spot:
Anyone seen anything like this before or know what it is? I'm hesitant to just dismiss it in case it's some kind of indication that something is wrong. But I hardly want to call the vet out just for some funny colored hair, too, in case it's just something not unusual, but that I just haven't seen before.