Looks like ring worm to me.
Max, my Morkie, had it when he came to us as a 16 week puppy. Even with vet care (sulfur dips, meds, shampoo,...) it spread quickly all over him and then to the entire family (6 of us) including the cat. No one was spared and I acted quickly. I was bleaching every thing I could in the entire house. It is contagious.
I would start putting on the cream for ring worm until you can get to a vet.