The discoloration of a dog's nose may be caused by malnutrition, seasonal factors, genetic factors, aging, trauma, disease, allergies, etc. It needs to be judged based on the specific situation of the dog. You can usually let the dog bask in the sun more and supplement the dog's nutrition, especially vitamins and trace elements. Do not let the dog eat plastic rice bowls or toys. If your dog’s nose discolors due to age or genetics, it’s fine.