I adopted a stray kitten once and got ringworm from him. It was not fun. I got him treated at the vet, and I had to go to my human doctor for ointment to put on the rash. If you do not do anything about it, it will only get worse and could become extremely serious. Until you can get your vet to a doctor or yourself to a doctor, I would try to avoid handling the dog, and even then, wash your hands very well.