Demodectic Mange results from the Demodex mite passing from the mother dog to her pups in the first few days after birth. Demodex mites live in hair follicles and typically don’t cause problems, but if your pup has a compromised immune system, demodectic mange can develop. It usually appears as patches of red, scaly, balding skin on the neck, head, and forelegs. It typically fades on its own. However, you should take your dog to the vet to prevent it from evolving to the general form of demodectic mange.