The whitening of ringworm in dogs is caused by fungal infection. It is necessary to clean up the dander and then spray the medicine on time until new hair grows in the ringworm area. You need to pay attention to hygiene, bathe your dog regularly, and be sure to blow dry the hair. Keep the indoor environment clean and disinfect regularly, and try to avoid taking your dog to dirty environments or coming into contact with other dogs with skin diseases.