There are two types of mange in dogs both caused by skin mites. Demodectic or Red mange is caused by a mite that is usually passed from the mother to the puppy. In fact puppies are most commonly affected because their immune systems are still developing and they don't have the ability to fight off this mite.
Demodex mites commonly inhabit the skin of adult dogs without incident. The immune system of the adult dog is capable of suppressing the mite so that it does not cause skin disease. Adult dogs that are immunosuppressed for any reason may come down with demodex but it is most commonly a self limiting disease of puppies. In most cases as the puppies immune system develops the mites cease to cause problems.
In some cases treatment is warranted and consists of topical ointments for small localized lesions. If your dog is unfortunate enough to suffer from
generalized mange over his entire body he may need to be dipped with a special product available at your veterinarian. These dips may need to be repeated several times over several weeks and prolonged treatment can be expensive.
A significant proportion of generalized demodex is self limiting too, meaning over time it will get better on
its own. Discuss treatment options with your veterinarian.
The more serious mange mite goes by the name of
Sarcoptes scabiei and causes the intensely pruritic skin disease called scabies. Pruritic is vet speak for really, really itchy. It can drive dogs and their owners crazy.
Hair loss accompanied by intense itching are the common signs of scabies. Unlike demodectic mange, scabies can occur in any age dog regardless of
their immune competence.
In both cases of mange, a diagnosis is made by a skin scraping that reveals the actual mite on microscopic exam. In scabies false skin scraping are common and they may need to be repeated
several times before the disease can be confirmed. It's important to understand that a negative skin scraping does not rule out scabies.
Treatment options include the same type of dip is used to control scabies and fortunately usually does the trick in fewer applications. I'd suggest that you leave the dipping to the vet as it's messy and the stuff is kind of toxic. Some of the newer topical flea and tick control products are also effective against scabies and are much easier than dipping. Your vet can recommend the best treatment for your dog.