Ok I've done a bit more research, and I think it may be birdcatcher spots??
The only difference is that they're not spots, its just two areas that are flecked with white... I'm not sure, and need some help.
There are two "spots", a little bit bigger than a half dollar, on both his shoulders, above his should blades, a bit higher than where my knees are when I ride bareback. Is it from bareback riding??? (It's hard to see the spot in the photo, but it's really obvious when you're standing next to him....)
He is only 5 years old, so it might be a genetic thing, but I wanted to make sure it wasn't sickness before anything else!
He has also had a bit of a runny nose, not bad, but just enough to make me concerned. I've stopped riding/excising him and I'm going to let him rest and keep an eye on him for the next 1-2 weeks... I think its just a virus, but I really want to be sure. I don't know much about horses yet, but my horse is my top priority!