The lesions caused by dermatophyte infections can sometimes be circular and appear like a ring, but oftentimes simply will result in a scaly, patchy hairless area of the dog. (dogcare.dailypuppy.com)
Other dogs may develop a skin rash (urticaria), apparent on hairless areas. (vcahospitals.com)
If you are using multiple creams it not only requires more hairless areas for application, but if you have fewer hairless sites for application it requires more applications over a longer period of time. (drvitaminsolutions.com)