There are a lot of hard scabs and dandruff on the dog's back, which may be caused by bacterial fungal infection or ringworm. The dog can be isolated first, and the home environment and the area where the dog lives can be comprehensively cleaned and disinfected. During the treatment period Wear an Elizabethan collar on the dog to prevent the dog from licking the medicine and causing discomfort. Dogs are very weak when they are sick, so they should be given nutrition in time. You can feed them some goat milk powder, nutritional paste, fish, etc. to enhance their resistance.