Consider ringworm. Google that under canine ringworm. If this turns out to be the case, know that it is contagious dog to dog, dog to cat, and dog to humans. Good handwashing keeps it away, as far as I have seen (I worked for a vet 8 years). Get back with your vet for a better dignosis, and correst treatment. Blessings - Blu
my dog is in the same plight.. it is possible it may be because of mites or sand fleas.. i have been cleaning the area with antiseptic and have been dusting him with ectoparasidal powder.. it has helped him( he used to lick them which he does no more) but still they continue to be there...