Demodectic mange, aka “red mange”, “follicular mange”, or “puppy mange”, is a canine skin disease caused by a tiny mite called Demodex canis. The mite cannot be seen with naked eyes because of its microscopic size.
The mange mites live in the inside of the hair follicles (thus the name “follicular mange”) and they are present in almost all dogs.
Nearly all puppies acquire the mange mites from their mother within a few days after birth. In small numbers, these mites cause no harm and do not cause any skin problems to the dog.
The life cycle of the mange mite takes about 20 to 35 days to complete. The mites are transmitted by direct contact only, because they can only live on the host’s body and cannot survive once they fall off the body.
Unlike scabies, demodectic mange is NOT a disease of overcrowded and dirty kennels. It usually occurs in puppies and dogs with weakened immune systems.
Symptoms of Demodectic Mange in Dogs
Demodectic mange can be localized or generalized.
Localized Demodectic Mange
About 90 percent of cases of demodectic mange in dogs are localized. Localized mange usually occurs in puppies under one year of age.
Because the mites live in the hair follicles, the first sign of demodectic mange in dogs is hair loss. You can see signs of hair-thinning around the eyelids, lips, and mouth corners, and sometimes also on the trunk, legs, and feet.
In some cases, the skin becomes red, crusty or scaly, and may develop a few (less than 5) isolated lesions which may or may not itch. These lesions usually self heal in 6-8 weeks when the puppy gets older and his immunity gets stronger.
Generalized Demodectic Mange
Dogs with generalized demodectic mange suffer from hair loss on the head, neck, trunk, and legs. The skin will become crusty, inflamed and infected, sometimes with clear oozing fluid.
Usually there is also a secondary bacterial infection. In more serious cases, the following symptoms will also be shown:
If a puppy under one year of age develops generalized demodectic mange, there is a 30 to 50 percent chance that the puppy will self heal. Dogs older than one year of age are unlikely to be able to have a spontaneous cure.
Diagnosis and Treatment
A vet usually makes a diagnosis by examining skin scrapings under a microscope. He can make a positive diagnosis if he finds the mange mites on the skin and skin lesions on the dog.
As mentioned above, most cases of localized demodectic mange will heal by themselves. To shorten the course of the disease, the vet may prescribe a topical ointment that contains benzoyl peroxide gel (e.g. Pyoben or OxyDex). It can be applied daily to the affected areas.
Generalized demodectic mange infestations are more serious and if you suspect your dog has the problem, take the dog to the vet immediately.
Treatment for generalized demodectic mange should be under close veterinary supervision. Conventional treatment includes the use of medicated shampoos and dips to remove surface scales and kill off the mange mites.
The FDA protocol of treating generalized demodectic mange in dogs is to first bath the dog using a benzoyl peroxide shampoo and then apply Amitraz dips every two weeks. Before dipping, medium-length and longhaired dogs be clipped short to facilitate access of the dip to the skin.
It is generally suggested that between 4 and 14 dips should be given to the dog at 2 week intervals. Bathing and dipping should be continued for 60 days beyond the day when skin scrapings first became negative.
Dogs that do not respond to dipping are sometimes treated with oral ivermectin or milbemycin. Since large doses of such medications may need to be given, close veterinary supervision is required.
If your dog is a Collie, Sheepdog, or other herding breeds and their crosses, DO NOT use Ivermectin because it may cause potential toxic effects in these dog breeds.
Finally, if the dog also suffers from secondary bacterial infection as a result of mange, the vet will also prescribe antibiotics.
If your dog suffers from a mild case of mange, you may want to first try using milder and natural home remedies for treatment.