Mange is a parasitic skin disease
caused by microscopic mites. Two different mange mites cause skin
disease in dogs. One lives just under the surface of the skin, while
the other resides deep in the hair follicles. Although both mites
share 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.
causes demodectic mange?
Demodectic mange, sometimes just
called "demodex" or “red mange”, is the most common form of mange in
dogs. It is caused by the demodectic mange mite, a parasite which
lives in the hair follicles of affected dogs. Under the microscope,
this mite appears shaped like a cigar with eight legs. All dogs (and
many humans) have a few of these mites on their skin. As long as the
body's immune system is functioning properly, these mites cause no
Demodectic mange most often occurs
when a dog has an immature immune system, allowing the mites to grow
rapidly. As a result, this disease occurs primarily in dogs less
than 12-18 months of age. In most cases, as a dog matures, the
immune system also matures. Adult dogs that have the disease usually
have defective immune systems.
this mean that demodectic mange is not contagious?
Yes. Since the mite is found on
virtually all dogs, exposure of a normal dog to one with demodectic
mange is not dangerous.
doesn't the immune system mature correctly in some dogs?
Development of the immune system is
under genetic or hereditary control. Thus, an affected dog usually
comes from a litter containing other affected puppies. Owners of
littermates should be alerted to watch for the development of mange
in their puppies. Because the disease is due to a genetic defect,
affected dogs should not be bred. Also, parents of the affected dog
should not be bred again.
does demodectic mange do to the dog?
Surprisingly, a dog with demodectic
mange does not itch severely, even though it loses hair in patches.
Areas of bare skin will be seen. The hair loss usually begins on the
face, especially around the eyes. When there are only a few patches
of hair loss, it is termed localized demodectic mange. If the
disease spreads to many areas of the skin, it becomes generalized
is demodectic mange treated?
The localized form is usually
treated with topical medication. The generalized form requires
shampoo therapy and a special dip or oral medication. Shampooing
with special cleansing shampoos helps to flush out the hair
follicles prior to dipping. Dipping is described below. For dogs
with generalized demodectic mange, secondary skin infections
complicate the condition requiring antibiotic therapy. Dogs with
skin infections often have very red, inflamed skin. This is the
source of the term "red mange."
heard that there is a drug that can be given orally for demodectic
mange? Is that true?
Yes, with some reservations.
Ivermectin is a drug that is used for prevention of heartworms.
It is also used for certain parasites on cattle. The cattle
preparation has been used orally for demodectic mange in dogs. In
some dogs it has proven to be successful. However, it is a very
strong drug that can cause severe side-effects, including death, if
it is not administered properly. It is not approved for use in dogs,
so we would only consider using it as long as you are willing to
accept liability for adverse effects.
is the prognosis for my dog?
Treatment of the demodectic mange
is generally successful. However, if the immune system is defective,
neither the mites nor the infection may respond to treatment.
successful treatment, is it likely to recur?
Because the immune system does not
mature until 12-18 months of age, a dog with demodectic mange may
have relapses until that age. It is important to treat as soon as a
relapse occurs to minimize the possibility of developing
uncontrollable problems. Demodectic mange may also occur in older
dogs because function of the immune system often declines with age.
Dogs who have immune suppression due to illness or medication are
also candidates for demodectic mange.
The dip commonly used for
demodectic mange contains the insecticide amitraz. It must be
used cautiously because it is a strong insecticide that can have
cause side-effects both to your dog and to you if not used
properly. Your dog may experience vomiting and sedation for 24-36
hours following each application. Most of these problems will
usually be self-limiting and resolve without medical intervention.
If this occurs, the dip should be diluted with 25% more water the
next time it is used. Since each dipping results in the development
of tolerance to the dip, your dog is less likely to have
side-effects with each subsequent treatment. Your dog should be
dipped three times at seven day intervals and then examined for the
presence of live mites or mite eggs. Further treatment will be
determined by the results. If you do the dipping yourself, be sure
to wear rubber gloves to prevent contact with your skin.
Instructions for your dog:
____ Apply the dispensed ointment to the areas of hair loss.
Do not get it in your dog's eyes. Apply it once daily for 10-14
days. At that time, the dog should be examined to decide if further
treatment is needed.
____ Give ____ ml of the oral insecticide once daily. This
needs to be continued for 2-4 weeks past apparent recovery. Report
any adverse side-effects including loss of appetite and vomiting.
____ Bathe your dog with the recommended medicated shampoo,
then rinse the shampoo. Next, slowly pour amitraz dip over the
entire body. This should be done three times at seven day intervals.
Mix one bottle of
amitraz with two gallons of water. Once the bottle is opened,
amitraz deteriorates rapidly, even if not diluted. Therefore, unused
dip cannot be used later. Wear rubber gloves while handling the dip;
wash your hands and arms with soap and water after treatment of your
dog. Do not rinse the dip off your dog; allow it to air dry. A hair
dryer may be used if the temperature is cool.
If vomiting or
sedation occurs within 24-36 hours after dipping, dilute the dip
with 25% more water (2˝ gallons instead of 2) the next time. These
side-effects should resolve without treatment. If your dog continues
to experience lethargy or vomiting beyond 36 hours or if your dog’s
condition worsens, notify the hospital for instructions.
____ After the third dipping, we should examine your dog for
the presence of live mites or mite eggs. The need for further
treatment will be discussed. Some dogs require up to 12-15 dippings
before no live mites or eggs are present. We should examine your dog
after every third dip.
____ Administer the dispensed antibiotics according to the
label. When the prescription is completed, your dog should be
examined to determine if further antibiotic treatment is needed.
____ For lesions on the feet, mix l cc of amitraz dip
(straight from the bottle) with 1 oz of propylene glycol. Apply this
mixture to the feet 2-3 times per week. It must be mixed fresh each
week. If the feet are affected, they will often be the last part of
the body to heal. You should be able to obtain propylene glycol at
your pharmacy. Remember to wear gloves when applying dip to your
____ At the first sign of recurrence of this disease, we
should see your dog again to determine what treatment is needed.
This may happen until it is 12-18 months old.
____ We will apply the amitraz dip to your dog. Return the
dog in ____ days for the next treatment.
Return your dog in ____ days to have it examined for the presence of