Dogs with ringworm often have a very characteristic set of symptoms. The classic symptom is a small round lesion that is devoid of hair. The lesion will often have scaly skin in the center. Small pustules are often found in the lesion. The lesion may start as a small spot and continue to grow in size. The lesion may or may not be irritated and itchy. The lesions are most common on the head but can also occur on the legs, feet, or tail. The condition can often appear like, and be confused with, demodectic mange. In some infections, the fungus will not be in a circle and can spread across the face or nose and look like an autoimmune disease.