Demodectic Mange in Dogs: Symptoms and Treatment

Demodectic mange is a skin problem that commonly occurs in dogs less than 18 months old. It is caused by the infestation of Demodex canis, microscopic mites that thrive in the hair follicles of the affected dog. These microscopic mites are already present in small numbers, on the dog's skin. Their population is kept in check by the immune system.

The parasitic infection can be either localized or generalized. In localized mange, specific parts of the body are affected. The parts most susceptible to this parasitic infection are the face, ears, abdomen, and the feet. An adult dog diagnosed with this skin disease, has a defective immune system due to an underlying medical condition.

The disease creates isolated patches of hair loss. The parasitic infection can be either restricted to small areas of the body (localized) or widespread, affecting the entire body. The onset of hair loss is usually around the eyes, muzzle and other portions on the head.

Dogs with localized mange, show mild symptoms as it is a self-limiting disease. Clinical signs include one or two areas of hairlessness, that may be itchy.

In generalized mange, there are more than 5 lesions, that may cover the entire body. A secondary bacterial infection is generally associated with generalized mange. Hair is sparse and the skin has a moist appearance. Some pets develop fever, become lethargic and lose their appetite.

In general, the symptoms of this infection are as follows:

• Hair loss
• Red, inflamed, itchy skin
• The skin is oily or greasy to touch

In most cases, lesions heal on their own, as the puppies get older. However, persistent lesions require treatment. Topical medications are generally used to treat the localized form of demodectic mange.

The treatment of the generalized form, includes the use of oral medication or shampoo therapy and a special dip. In case, the affected dog is suffering from secondary skin infections, doctors also recommend antibiotic therapy.

Fortunately, 90% of the cases are localized, in which only a small portion of the body is affected. An effective treatment that has been recommended for years, involves daily application of 1% rotenone ointment or a 5% benzoyl peroxide gel.

However, the preferred treatment is the application of Amitraz dips, every 2 weeks. Amitraz is a strong parasitic drug and is sold under the product name Mitaben. It is necessary to wear rubber gloves, when administering the drug. Ivermectin (Ivomec) is another anti-parasitic medication prescribed by veterinarians.