Sarcoptic Mange (Scabies) in Dogs

Overview of Canine Scabies

Sarcoptic mange (also known as scabies) is a highly contagious parasitic disease caused by a microscopic mite called Sarcoptes scabiei that affects animals and people. These mites invade the skin of healthy dogs and puppies and create a variety of skin problems. Humans exposed to infested dogs commonly are affected.

Dogs of all ages may be affected, but sarcoptic mange is more common in young animals. Cats living in close contact with affected dogs may develop the disease. The mite prefers to live lives on the surface of the skin, and does not survive for very long off the host.

The hallmark of the disease is intense pruritus that does not respond to symptomatic treatment; the dog scratches and chews at himself. There may also be papules (small red bumps) located on the margins of the ears, elbows, hocks (ankles), chest and abdomen. These lesions may become generalized. Other symptoms may include patchy hair loss, and crusty sores.
Symptoms are thought to be the result of a severe allergic reaction to the mite. Just a few mites can cause severe generalized pruritus (itchiness), which sometimes persists after therapy due to the allergic component of this disease. The incubation period (time until clinical symptoms become apparent) can be as long as 3 weeks after exposure.

If left untreated, chronic skin lesions develop including increased pigmentation, thickening and wrinkling of the skin, ulcerations and draining tracts. Secondary bacterial infections are common due to self-trauma.

Pruritic (itchy) papules (small red bumps) can be found on the arms, neck and waistline of affected humans. The sarcoptic mange mite of dogs cannot reproduce on human skin, and lesions on humans regress spontaneously in 12 to 14 days.

What to Watch For

Signs of Sarcoptic Mange in Dogs may include:

Diagnosis of Sarcoptic Mange in Dogs

The diagnosis of sarcoptic mange is based on three things:

Treatment of Sarcoptic Mange in Dogs

Treatment should be carried out for the entire life cycle of the mite, which is 3 weeks. All animals in the household should be treated to reduce the possibility of re-infestation.

There are several ways to treat scabies.

Home Care of of Sarcoptic Mange in Dogs

At home you may be asked to bathe your animal weekly and use an anti-parasitic lime sulfur dip (LymDip). The dip preparation is very safe, but may damage jewelry and porcelain. It produces a yellow stain on the hair coat and skin due to its sulfur content. The sulfur content also imparts a strong odor of “rotten eggs.” Gloves should be used when applying the dip.

Ideally, the dip should be applied outdoors and the animal not allowed back into the house until it is completely dry. This precaution will prevent staining of furniture and carpeting by the dip.

Mites do not survive for long in the environment. Regular cleaning, vacuuming and washing of bedding usually are sufficient to rid the household of the mites. Remember, mites can be transmitted to humans, so care must be taken when handling an infested dog.

Preventative Care for of Sarcoptic Mange in Dogs

Prevention consists of avoiding contact with infected animals. Mites do not survive very long in the environment, and direct contact is necessary to become infected. All animals in the household should be treated to reduce the possibility of re-infestation.

Regular cleaning, vacuuming and washing of bedding usually are sufficient to rid the household of the mites.

In-depth Information for Sarcoptic Mange in Dogs

Sarcoptic mange is a contagious parasitic skin disease of dogs caused by Sarcoptes scabei. The mite is fairly host specific but can infest man and cause a transient pruritic papular eruption. In people lesions develop within 24 hours after exposure and spontaneously resolve in 12 to 14 days because the mite cannot reproduce on human skin.

The mite spends its entire life cycle on the host. The life cycle is complete in 17 to 21 days. Male mites live on the surface of the skin while females burrow into the superficial layers of the epidermis to lay eggs. Mites do not survive off the host longer than 48 hours in most conditions.

Incubation period for scabies varies from six to 30 days depending on previous exposure. If a dog has been exposed to the mite previously, clinical signs are more rapid and severe due to existent hypersensitivity.

Very few mites can cause severe clinical signs. This is most likely due to development of hypersensitivity from the host. Mite feces are the most likely source of antigenic stimulation.

Sarcoptic mange cannot be ruled out by the absence of clinical signs in other animals or people living in the same house. This is due to the limited number of parasites present in most affected animals.

Besides the classic presentation of scabies, there are two rarer syndromes:

Diagnosis In-Depth of Canine Sarcoptic Mange

The diagnosis of sarcoptic mange is made on the basis of suggestive history, compatible clinical signs, microscopic examination of skin scrapings and response to therapy. Response to therapy sometimes is used as a diagnostic test because the sarcoptic mange mites can be very difficult to find on skin scrapings. Your veterinarian will probably recommend the following:

Treatment In-Depth of Sarcoptic Mange in Dogs

All extremely pruritic dogs with typical clinical symptoms should be treated. Dogs with non-seasonal pruritus that is poorly responsive to treatment with cortisone-like drugs (glucocorticoids) should be treated for sarcoptic mange to rule out this possibility.

All animals in the household should be treated. Various treatments may be used to eradicate sarcoptic mange mite infestation. They include:

In most dogs with sarcoptic mange, pruritus is reduced by at least 50 percent 7 to 10 days after the first treatment and pruritus gradually disappears within 4 weeks.

Amitraz should be used at 25 to 50 percent strength in toy breeds due to increased risk for toxicity in smaller breeds. Sedation is the most common adverse effect of amitraz. Amitraz should not be used in geriatric or sick animals and in those with diabetes mellitus because amitraz may cause a temporarily high blood sugar level.

Follow-up for Dogs with Scabies

Prevention consists of avoiding contact with infected animals. Mites do not survive very long in the environment, and direct contact is necessary to become infected.

Therapy must be carried out over the entire life cycle of the mite (for 3 weeks). With appropriate therapy, pruritus and skin lesions should resolve completely.