Symptoms that indicate your dog may have mites include dandruff, itchiness and hair loss. A veterinarian should diagnose mites because there are other skin diseases that cause very similar symptoms and the parasites are not always visible.
The type of mites that your dog has may change the symptoms. Demodectic mites tend to cause hair loss and sores. Your dog may have visible scabs on its body. This type of mange typically is not itchy, but the sores can become infected, causing irritation and itchiness. Demodectic mange is not infectious because it is caused by mites that live on all dogs. Dogs with this type of mange usually have an underlying illness or condition that allows the mites to overpopulate.
Sarcoptic mange is more associated with itchiness, often the first noticeable symptom. Your dog may become restless and scratch constantly. Symptoms usually appear first on the ears, face and legs, but it can affect any part of the dog's body. Sarcoptic mange is highly contagious and can even affect humans, so you should isolate the affected dog away from other pets until you finish treatment.
If your dog has mange, your veterinarian can prescribe medications to kill the mites. This may take the form of pills or topical treatments, depending on the situation.