The redness of white-coated dog hair is generally caused by malnutrition, improper diet, poor care and other reasons. First of all, the dog needs to be supplemented with nutrients. Let the dog eat more vegetables, fruits, egg yolks, fish oil, and lean meat. When waiting for food, don’t give your dog food that is too oily or salty. At the same time, the dog should be bathed and dewormed regularly, let the dog bask in the sun more, and if the hair is dirty, clean it in time. If you persist for a period of time, the dog's hair will turn white.