Where Does Mange Start on a Dog's Body?

A mother dog with mange can infect nursing puppies.
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Mange is a skin condition in dogs and other mammals caused by microscopic mites. The adult arthropods have eight legs, while the larvae display six legs. When the mites infest your dog, mange occurs. Two types of mites can afflict your dog, either burrowing or non-burrowing. Burrowing mites live under your dog’s skin, while non-burrowing mites prefer living in hair follicles or on the surface of the skin. These two mites, the Demodex canis mite and the Sarcoptes scabiei mite trigger the two types of mange that infect dogs.

Most Common Mange

The most common mite species that lives on the skin of dogs is the Demodex mite. Small amounts of these mites naturally live on your dog’s skin. Infection occurs if the mites reproduce into large numbers on your dog’s skin and hair follicles. This usually happens if he cannot fight the infection due to sickness or a weak immune system. Newborn puppies can contract Demodex mites from their mother while nursing. This type of mange is not contagious to humans.

Contagious Mange

Sarcoptic mange is the more contagious of the two mange infections and can spread to humans with direct contact. In humans, this condition is known as scabies. Burrowing female Sarcoptes mites tunnel under your dog’s skin where they lay eggs for up to three weeks. After about five days, the eggs hatch and grow to adulthood. The adults return to the surface of the dog’s skin and mate, beginning the cycle again. The life cycle takes 14 to 21 days to complete and symptoms begin during this time.

Skin Symptoms

Demodectic mange begins as an itchy, red rash with scaly, bald spots around your dog’s face, especially his eyes and mouth. If the dog is healthy, his immune system may prevent the mange from spreading, but if the mange spreads to your dog’s chest and legs, a veterinarian must treat it. Severe cases of demodectic mange can cause foul-smelling, pus-filled blisters that bleed and spread throughout the body.

Sarcoptic mange is extremely itchy, making your dog scratch incessantly. He will begin to lose fur and develop a red rash, lesions and scabs around his ears and face, which then move to your dog’s elbows and abdomen.

Diagnosis and Medical Treatment

If your dog develops symptoms of mange, your veterinarian can take skin scrapings to determine if mites are present. When your dog scratches the infected area, the mites can die and the veterinarian may not be able to see them through skin scraping or biopsies. In this case, the veterinarian may prescribe medication to treat the mange and watch for a few weeks to make sure it has cleared up. Any other dogs in your household should also be treated. Some dogs, such as collies, Shetland sheepdogs and Australian shepherds can have allergic reactions to the medication, Ivermectin, which treats mange, according to VeterinaryPartner.com, so consult your veterinarian if you own one of these breeds.

What You Can Do

If your dog is diagnosed with mange, wash his bedding and collar, along with any harnesses, sweaters or boots he may wear. If you have other dogs in your household, wash their bedding, as well. You can help prevent infestation by keeping your dog away from strange dogs and from coming in contact with wildlife.