Demodectic Mange in Dogs: Symptoms and Treatment

This is a skin problem that commonly occurs in dogs less than 18 months old. Microscopic mites attack the body that give rise to this skin disease. The demodectic mange mite thrives in the hair follicles of the affected dog. All dogs have this mite (demodex canis) in small numbers, on their skin. These mites cannot cause any harm, if the immune system is functioning properly. Demodex canis is invisible to the naked eye and can be observed only under the microscope. Studies have shown that only certain breeds of dogs are vulnerable to this skin disease.

Causes

The 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, ear and feet. This parasitic infection is often diagnosed in puppies, who have an underdeveloped immune system. This disease occurs when there is rapid growth of mites that cannot be stopped by a poorly developed immune system. An adult dog diagnosed with this skin disease, has a defective immune system due to an underlying medical condition.

Symptoms

The disease creates isolated patches that are devoid of hair. 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 but 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
• Inflammation of skin
• Red skin
• Itchiness
• The skin is oily or greasy to the touch

Treatment

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 the usage of 1% rotenone ointment or a 5% benzoyl peroxide gel that is applied daily. 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.

In case your dog experiences patchy hair loss or scratches excessively, you must immediately contact a veterinarian as delayed treatment can make matters worse.