Is the infection "pyoderma" - if so, that is staph intermedius and is most usually seen in dogs who have allergies. The gold standard treatment is w/ Simplicef x 30 days. From there, you have to treat the allergies or it will likely come back over and over. Read about how to approach and treat allergies here:
http://www.yorkietalk.com/forums/die...tart-here.html