The dog's double-headed ears are not dirty. It may be that water, bugs or other foreign objects have entered the ears. It is best to carefully check whether there are any foreign objects in the dog's ear canal. If you don't see any foreign objects, you can take the dog to the hospital. See a doctor at a pet hospital for a checkup. Generally, this situation is abnormal, indicating that there is a problem in the dog's ears and needs to be checked in time to avoid delaying treatment.