Hard shackles on the dog's foot pads may be caused by normal wear and tear, canine distemper or malnutrition. It is necessary to observe whether the dog has other abnormalities. If the dog has poor energy, loss of appetite, vomiting and diarrhea, and a dry nose If you wait for symptoms, it may be canine distemper. It is best to take your dog to the pet hospital for examination and treatment immediately. If there are no other abnormalities, then you don’t need to worry too much. Just pay attention to supplementing the dog’s nutrition.