Lindale Veterinary Clinic / Demodectic Mange

Demodectic Mange

(SOMETIMES CALLED "RED MANGE")

THE CULPRIT - DEMODEX CANIS

Demodectic mange is caused by a microscopic mite called Demodex canis. All dogs raised normally by their mothers possess this mite as mites are transferred from mother to pup via cuddling during the first few days of life. (After the pup is older it is unable to pick up demodex mites. Puppies raised by hand, do not ever get demodex mites.) For some reason, conditions change in certain dogs to allow demodex mites to "gain the upper hand;" the mites proliferate and can cause serious skin disease.

Mites are not transmitted to people or other dogs except from mother dog to pup as described. Demodectic mange (unlike Sarcoptic mange) is not contagious.
Mites live inside hair follicles -- a difficult place for miticides (chemicals that kill mites) to reach.
Mites are a normal residents of dog skin; it is only in some individual dogs that mites cause problems.

DEMODICOSIS -- THE DISEASE ITSELF

Demodectic mange -- also called "demodicosis"-- has three forms:

FORM #1: LOCALIZED

Usually a red, scaly, well-circumscribed lesion on the face or forelegs is present. It generally goes away on its own. Goodwinol ointment, an insecticide, may be used daily to control localized demodicosis. Hair regrowth should be evident after about a month of treatment; however, some localized cases appear "destined" to become generalized and no treatment will prevent this from occurring.

When ointment is used, rubbing the medication on the area may break off the weaker hairs at the margin of the lesion. The lesion may thus appear to get larger at first. Antibacterial gels are also used against localized demodicosis and associated skin infections. Often it is best not to treat this condition and to simply allow it to resolve on its own.

Enlarged lymph nodes are a bad sign -- often foretelling generalized mange.

CAN THE PUP BE BRED LATER?

Sometimes the puppy with localized demodicosis was obtained for breeding purposes. The current recommendation is not to breed these puppies. It is best to be conservative and not take the chance of passing on genetic predisposition for this disease.

Localized demodicosis is almost exclusively a "puppyhood" disease. When a puppy develops localized demodicosis the chance of the condition resolving is 90% unless there is a family history of demodicosis in related dogs. In this case, chance of spontaneous resolution drops to 50%.

Occasionally an adult dog develops localized demodicosis. We currently do not have good understanding of the prognosis or significance of this condition in an adult dog.

FORM #2: GENERALIZED

The entire dog is affected with patchy fur, skin infections, bald, scaly skin.

Most generalized demodicosis starts as localized demodicosis.

ADULT ONSET-- Most demodicosis occurs in young dogs. An older dog should not
get deodicosis unless it has an underlying problem with its immune system, possibly even cancer. A veterinarian should be consulted regarding possible primary diseases.

JUVENILE ONSET -- 30-50% of dogs under age 1 year recover spontaneously from generalized demodicosis without any form of treatment. Usually treatment is recommended, though, to facilitate recovery.


	IT IS VERY IMPORTANT THAT DOGS WITH A HISTORY OF DEMODECTIC MANGE NOT BE BRED AS THERE IS A HEREDITARY COMPONENT TO THE DEVELOPMENT OF THE DISEASE


	FORM #3: DEMODECTIC PODODERMATITIS


	This condition represents demodectic mange confined to the paws. Bacterial infectious usually accompany this condition. Often as generalized demodicosis is treated, the foot is the last stronghold of the mite. Old English Sheepdogs and Shar-peis tend to get severe forms of this condition. The infection can be so deep that biopsy is needed to find the mites and make the diagnosis.

STRESS AND GENERALIZED DEMODECTIC MANGE

Physiological stress is an important factor determining the degree of severity of demodectic mange.

Females should be spayed as soon as the disease is controlled. Coming into heat, hormone fluxes, and pregnancy are very stressful. Also, predisposition to demodicosis is hereditary and should not be passed on.
The dog should be fed a reputable brand of dog food so as to avoid any nutritionally related problems.
Keep the pet parasite-free. Worms are irritants that the pet need not deal with and fleas may exacerbate the itchiness and skin infection.
Keep up the pet's vaccinations.
The mites themselves cause suppression of the immune system so the pet needs every advantage to stay healthy.
Skin infections are usually present in these cases and antibiotics will likely be necessary. It is very important that cortisone type medications such as prednisone NOT be used in these cases as they will tip the immune balance in favor of the mite.

PROGNOSIS

The younger the dog, the better the chance of cure. In many cases of adult-onset demodicosis, the disease is controlled by dips and baths but cure is not always possible. Some cases can never be controlled.

RELAPSE?

Relapse is always a possibility with generalized demodicosis but most dogs that relapse do so within a 6-12 month period from the time they appear to have achieved cure. When relapse occurs it is often because the dog appeared to be normal and the owner did not return for the appropriate rescrapings. The final scrape is performed one month after treatment has stopped.

SARCOPTIC MANGE IS A COMPLETELY DIFFERENT DISEASE.

WE WISH IT WASN'T NECESSARY TO ADD THIS

In older times, some 30 years ago, dipping dogs with demodectic mange in motor oil was a popular home remedy. Skin exposure to motor oil can cause rashes and skin destruction in severe cases. The hydrocarbons can be absorbed through the skin and cause a dangerous drop in blood pressure. If motor oil is licked off the coat, resultant vomiting can lead to aspiration of motor oil into the lungs and pneumonia. Kidney and liver damage can result from motor oil dipping.

PLEASE: DO NOT DIP YOUR DOG IN MOTOR OIL!