Great dane skin spots??

Great dane, around 5 and otherwise healthy. Weighs about 170 and his vet says it’s a healthy weight for his size. for the past few weeks/months he’s been getting these skin spots? they almost look but scabs but they aren’t. kind of like a scaly bald spot? they don’t seem to be bothering him and he doesn’t have any cysts/tumors as far as I can tell. any idea what it is? i’m worried it’s cancer but i’m hoping it’s maybe just a weird reaction to something in his environment or old age or something like that.