Pretty hard to tell from a photo, and of course we are not veterinarians. But if this were my puppy, and it was spreading instead of going away within two or three days, I would take the dog to a vet to get checked out.

 

Ours had one that appeared similar, which rapidly became infected, so that was a round on antibiotics. She kept getting rashes, vet diagnosed as allergies. We give her apoquel and haven't seen a rash since. Talk to your Vet.

 

What region do you live in? (Still in winter? Spring is well under way, with frost being a distant memory?) Do the spots smear or change when you run a damp Q-tip over them? Does the Q-tip pick up a red stain?