With the combination of these little white things and him having something painful and unknown on his tummy, I'd suggest taking him to the vet's. Better one time too many than one time too few.I think they are coming off. I have a lot stuck to my hand after checking him. He also has something on his tummy that i think is painful for him cause he doesn't let me see it. It had a bit of matted fur and something that looks like a black scab, but i am not sure if it is a scab or just his black fur. It felt a bit raised