Dogs have many parasites, both internal and external.  Internal parasites are those which live in the various organs inside the dog's body.  External parasites, such as fleas, ticks, and mites, live on the outside of the body. 

Mange is a parasitic skin disease caused by microscopic mites. Two different types of mange mites are significant in dogs.  One type lives just under the surface of the skin, while the other type resides in the hair follicles.  Although both types of mites share some similar characteristics, there are also important differences.  It is important not to confuse the two types of mange because they have different causes, treatments, and prognoses.

Contributing Factors

The sarcoptic mange mite is highly contagious between dogs.  Exposure to a dog infested with this mite will likely lead to spread of the parasite.

Prevalence

Sarcoptic mange is a common parasitic skin disease of dogs.

Causes/Transmission

Sarcoptic mange is caused by a mite that burrows just beneath the surface of the skin.  It may also crawl around on the skin surface.  This mite feeds on material in and on the skin.

Clinical Signs

The presence of the sarcoptic mite causes severe itching.  The dog will chew and scratch its skin constantly.  This leads to the loss of large amounts of hair, especially on the legs and belly.  Eventually, the skin will become thickened and will darken due to pigmentation.  Frequent scratching and rubbing often leads to secondary skin infections.

Diagnosis

Diagnosis is made by a skin scraping that is examined under the microscope.  However, only a small number of mites may be present.  Because of this, a dog may be strongly suspected of having sarcoptic mange but multiple skin scrapings are negative.  A presumptive diagnosis can be made because the signs are quite typical.  Age is not a significant factor in sarcoptic mange.  Although most common in puppies, dogs of all ages are at risk.

Treatment

There are several insecticides that are effective against this mite.  Various dips have been used successfully.  Dipping should occur weekly for at least 4 weeks, at which time your dog should be re-examined to determine if further treatment is needed.  An oral product, ivermectin, is also effective.  This drug is approved for use in preventing heartworms; it is not officially approved for use in treating sarcoptic mange.  However, its ease of administration compared to dipping makes it the drug of choice in certain situations, and it may actually be more effective than dipping in some dogs

Prognosis

With appropriate therapy, the prognosis for recovery is excellent.  Re-infestation from a contaminated environment or other dogs is possible.

Transmission to Humans

Sarcoptic mange is highly contagious to other dogs; it is also contagious to humans.  The dog's bedding should be washed in hot water with bleach or, preferably, discarded.  The mites are not able to complete their life cycle on humans; therefore, they will die in a few days without treatment.  However, they will cause quite a bit of itching before they finally die.

Instructions

____ 1) Bathe your dog in any good pet shampoo then slowly pour the diluted dip over your dog(s).  This should be done on a weekly basis for 4 weeks.  Carefully read the dilution instructions on the bottle.  Do not rinse off the dip; air drying is preferred.  A towel or hair dryer may be used, especially if the temperature is cool.

____ 2) Give your dog ivermectin orally _______________________________________.

____  3) Your dog's bedding should be washed in hot water with bleach or discarded.

____ 4) If relief from itching does not begin within 5 days after treatment begins, please call us.

____ 5) Allow us to re-examine your dog in ____ days.

____ 6) Contact your physician if any family members develop an itching skin rash.  Tell your physician that you have been exposed to sarcoptic mange (also known as scabies).  In people, the mite cannot complete its life cycle so it will die in a few days.  However, it may cause itching during that time.  Reinfestation from the dog or premises can result in continued itching.