Signs Symptoms and Treatment of Demodectic Mange in Dogs

" Demodectic mange in dogs (red mange) is caused by a specific type of mite that burrows into your dogs skin. Reactions can occur in dogs that have a problem with the immune system and is particularly seen in younger or older dogs for this reason. Treatment includes the use of a dip or prescription medication. "

Demodectic mange in dogs is a skin disease of dogs that occurs when large number of Demodex canis mites inhabits hair follicles and sebaceous glands (sweat glands).  A small population of this mite is part of normal flora of the dermis (skin) and doesn’t cause any harm or infestation threats to the host or of clinical importance. In general, the disease condition develops when there is a problem with the immune system. This includes under developed immune systems in younger dogs and suppressed immune systems in older dogs.

Signs & Symptoms of Demodectic Mange in dogs:

Usually alopecia (Hair loss), redness, scabs and no or low itching is associated with red mange. Clinically this disease has two forms, localized and generalized. Localized red mange is common in young dogs, under the age of 2 years. This form is considered as self resolving; the condition improves spontaneously and can be left untreated.  

Alopecia is the initial sign of condition; the mites reside in the follicles of hairs, thus removing hairs from its cavity resulting in hair loss. The skin appears to be oily and moist, while hyper pigmentation is seen. Itching is usually of low degree or absent. These circular patches usually heal by themselves in 3 – 5 weeks, as the immunity of the dog improves.

Some localized red mange cases develop into a diffused localized form where most of the effects are to the skin (involving deep skin tissues. called the Integumentary system) or it evolves into a generalized form ( involves other systems of body other then integumentary system, such as the lymphatic system – related to lymph & immunity & thermo regulatory system – related to inflammatory response center in the brain).

The generalized from of this disease occurs only when there are heavy infestations of mites, or a much weakened immune system.  Symptoms can include low degree itching, along with loss of hair over the coat at the head, neck, abdomen, legs, and feet. The condition in medical terminology is called pyodermodecosis, which means that puss, or fluid oozes from the affected areas, usually at the head, neck and dorsal abdomen area. Skin tissues become sensitive and inflamed.  Due to secondary bacterial infection, a dog may experience systemic illness, fever, lethargy, lymphadenopathy (swollen lymph nodes), cellulitis (Spreading bacterial infection deep in to skin tissues), weakness and more suppressed immune response.

Pictures of Red Mange

Diagnosis of Demodectic Mange in Dogs

Red Mange is usually diagnosed by presence of Demodectic canis mites in deep skin scrapings. It is highly recommended that when ever the generalized form of red mange is diagnosed in adult dogs, complete medical evaluation or screening should be carried out for other diseases such as heartworm disease, hypothyroidism etc.

Canine Red Mange Treatment

For the superficial localized from of disease, if the patches are fewer and smaller in size, it may be left untreated. Prognosis for such lesions is good, spontaneous recovery is frequent, and conditions improve as the dog grows older, as the immune response improves with the age.

On the other hand diffused localized red mange should be handled with care, as this form converts to generalize form. Generalized demodecosis, pyodemodecosis, and podo demodecosis, the prognosis is always being guarded, i.e. the prognosis depends upon the developing disease.

In general, hair clipping of affected area, cleansing with benzoyl peroxide shampoo is recommended, so that hair follicles may be flushed. Whole body dips with Amitraz (0.025%) which is available only by prescription, every two weeks is approved and recommended treatment for generalized red mange.

You could also effectively use the dip offered over the counter by Naturasil that is mixed with your dog’s shampoo. This can help your dog accept treatment since your dog is already used to the shampoo. It contains sulfur-lime, which is a keratolytic product, i.e. Compounds which remove keratin from scales on skin. Scales harden the skin, so a product that removes keratin can help. Naturasil when mixed with shampoo softens the scales and makes skin softer & thus lesions heal rapidly. It should be noted that, on application of a keratolytic product, scales may worsen initially, but with in days of regular bathing, scales are removed and the skin becomes softer.

If you prefer, mix the Naturasil dip with a natural shampoo forumlated to help with mites such as the PetAlive Manage Mites Shampoo. It is a cleansing herbal shampoo that promotes healthy skin in dogs and can help with mite infestations naturally.

Ivermectin and Moxidectin injections are used for the generalized condition of disease.  Secondary bacterial infections should be followed with an appropriate antibiotic therapy, along with supportive therapy of multi vitamins and mineral supplements.

Side Effects:

Toxic effects of the different therapeutic protocols have been reported, which should be monitored with a gradual increase in dosage of different anti parasitic drugs during therapy. Similarly Ivermectin has adverse effects on different breeds as collies and collie crosses.

Precautions for Demodectic Mange in dogs:

Dogs infested with Demodectic mites should not be used for breeding, until at least 2 consecutive negative skin scrapings are obtained at an interval of one month each.

A dogs environment should be thoroughly cleaned using a disinfectant designed to kill mites such as Benzarid.  All of the dogs belongings shoudl be washed as well.

References for Demodectic Mange in Dogs:

Merck Veterinary Manual (13th Edition, Merck & Co. 2008)

S. Hayat, Laboratory Manual of Veterinary Parasitology (2007)