Demodectic mange in Dogs

Demodectic mange is a skin disease caused by a tiny mite called Demodex canis, which cannot be seen with the naked eye. This parasite lives in the hair follicles of dogs. Demodectic mange, sometimes just called "red mange", is the most common form of mange in dogs. Dogs with demodectic mange usually do not itch severely, even though it loses hair in patches.

Cause

Nearly all dogs acquire mange mites from their mother during the first few days of life. These mites are considered normal skin fauna when present in small numbers.

Mites produce this disease only when an abnormal immune system allows their numbers to get out of control. This occurs primarily in puppies and in adult dogs with lowered immunity.

Transmission

Demodectic mange is not contagious to other animals or humans. Demodex mites are transmitted to puppies from their mother during the first few days of life. Since the mite is found on virtually all dogs, exposure of a normal dog to one with demodectic mange is not dangerous.

Demodectic mange has two forms;

• Localized Demodectic Mange
• Generalized Demodectic Mange

Localized Demodectic Mange

This disease occurs in dogs under 1 year of age. The appearance of the skin is similar to that of ringworm. The principal sign is thinning hair around the eyelids, lips, and corners of the mouth, and occasionally on the trunk, the legs, and the feet. The thinning progresses to patches of ragged hair loss about 1 inch in diameter. In some cases the skin becomes red, scaly, and infected.

Generalized Demodectic Mange

Dogs with the generalized disease develop patches of hair loss on the head, legs, and trunk. The hair follicles become plugged with mites and skin scales. The skin breaks down to form sores, crusts, and draining tracts, presenting a most disabling problem. Some cases are a continuation of localized mange; others develop spontaneously in older dogs.

Diagnosis

The diagnosis is made by taking multiple skin scrapings and looking for the mites. Demodectic mites are usually easy to find. Under the microscope, this mite is shaped like a cigar with eight legs.

Treatment

• Localized Demodectic Mange can be treated with a topical ointment containing either benzoyl peroxide gel, or a mild topical preparation used to treat ear mites. It can be massaged into affected areas once a day.
• Generalized demodectic mange must be treated under close veterinary supervision. It involves the use of medicated shampoos and dips to remove surface scales and kill mites. Shave or clip hair from all affected areas to facilitate access to the skin.
• The treatment protocol involves first bathing the dog with a medicated benzoyl peroxide shampoo to remove skin scales. Allow the shampoo to remain on the dog for 10 minutes before rinsing it off.
• Completely dry the dog.
• Amitraz currently is the only miticide which is effective in treating demodectic mange in dogs.
• Be sure to treat the dog in a well-ventilated area and wear rubber or plastic gloves to keep the chemical off your skin.
• Sponge on the dip over a 10-minute period, allowing the dog’s feet to soak in the rinse. Allow the dip to dry on the dog.
• Repeat every two weeks, or as directed by your veterinarian.
• Secondary skin infections should be treated with antibiotics,
• Antihistamines can be used to control severe itching.

Side effects of Amitraz;

• Drowsiness
• Lethargy
• Vomiting
• Diarrhea
• Dizziness
• Staggering gait

Puppies are more susceptible than adults to these effects. If such a reaction occurs, immediately remove the miticide by thoroughly rinsing the coat and skin.