Demodex in the dog is a common
infestation of the dog’s skin with tiny, cigar-shaped, eight-legged mites.
Human demodex cases do occur but transmission from the dog to a human is
quite rare. Nevertheless, human cases of demodex do happen where transmission
from a family pet to a human occurs. (See a case of demodex in a
human below.) The mites reside and feed in the hair follicle and
oil glands of the skin. Also called Mange, which is a general term
used to describe any kind of mite infestation, Demodex is generally less
severe than Sarcoptic
mites (often called scabies).
Fortunately, most cases of
Demodectic mites are self-limiting… that is, the animal is able to arrest
the reproduction and growth of the mites and eventually repair the damage
they do. Once eliminated, most dogs do not acquire another infestation;
the dog’s immune defenses are primed to eliminate any new Demodex mites that
happen to find themselves on the dog. However, there are certain
individual dogs that, because of genetic programming, do not produce the
specific immune factors that will target the mites for destruction.
specific lack of adequate immune defense against the mites is a hereditary
aspect of the disease that can predispose an infested dog to a severe, unresponsive
case of Demodex. Many veterinarians believe that all dogs have small
numbers of Demodex mites residing in the skin and that having a few mites
is normal and common. It is when immune related, or nutritional or environmental
stresses impact the dog that visible skin lesions from mite infestations
become noticeable. Seen most commonly in young dogs, and rarely in
cats, Demodex skin lesions are usually transient, but occasionally in certain
individuals the mites will totally overwhelm the dog's skin. See the
photo below of a year old Doberman Pinscher with severe, generalized Demodicosis
that was totally unresponsive to all attempts at treatment. Adult-onset
Demodicosis is explained below.
QUESTION: Can Demodex
mites be inherited?
|The images below on
the left and right are photos that when clicked on will open in a new window
for a close-up look. In the center below you can view a video through
a link to YouTube.com of a demodex mite that was taken from a skin scraping
of an affected dog.
|View a live demodex
mite through the microscope, just as if you were the veterinarian looking
for this skin parasite. The video open on YouTube.com in a new window
so you can close that window when finished viewing the video and be right
See the video!
ANSWER: No. The mites are not present on the fetus while
the fetus is developing from an embryo in the uterus. However, if
the mother has Demodex mites present in/on her skin, the mites can invade
the new fetus’ skin immediately after birth. Since many dogs have
Demodex mites present in their skin, and never actually develop noticeable
skin lesions, the mother may not even be showing any signs of mites and
yet transmit mites to the newborn pups. The pups may or may not develop
a clinical case of mites.
then, do I keep hearing that Demodex can be inherited.
ANSWER: The problem is the wording. The specific antibodies
that will defend against infestation of Demodex can be inherited and most
dogs have those immune factors and are able to defend against Demodex.
But some individuals have inherited a deficiency of those antibodies and
just don't have the ability to fend off the mites. So the ability
to resist the mites, or not resist, is inherited. The actual mites
are not inherited.
QUESTION: So if I have a pup that has Demodex and it is only
six weeks old and has never been in contact with any dogs
outside our home, the mites must have come from the mother.
But the mother has never had Demodex so how could that happen?
ANSWER: Your assumption that the mother dog has "never had"
Demodex is probably not valid. Demodex mites have been proven to
inhabit the hair follicles of many, many dogs, humans and other mammals
without causing the host any problems at all. So these mites can
be present in normal and healthy individuals (who have inherited the immune
factors needed to keep the mites suppressed). So just because you
have not experienced a visible skin lesion on your dog does not mean that
the dog has no mites present.
QUESTION: If I have a dog that has Demodex, does that mean
I should not breed it?
ANSWER: If the dog, male or female, has a protracted, difficult-to-cure
case of Demodex, that dog should not be bred. If you have a dog
that has or had a brief, localized episode of Demodex and has recovered
well, then breeding may be considered; but some veterinarians believe that
any dog that has displayed skin manifestations of Demodex should be removed
from a high quality breeding program.
|I asked David Senter, DVM,
of Englewood, Colorado, a Board Certified Specialist in Veterinary Dermatology,
the next question because there seems to be quite a bit of confusion regarding
this issue. Dr. Senter specializes in the diagnosis and treatment
or management of all skin, ear and nail diseases in animals. Below
is his response...
a young dog has been diagnosed with Demodex, is it best NOT to spay or
neuter the dog until the Demodex has been cleared up?
ANSWER: From Dr. Senter: "Most dermatologists will elect not
to treat a dog with generalized demodicosis unless it has been
spayed or neutered. The reason for this is simply due to the high
likelihood of the affected dog's offspring to develop demodicosis. There
is absolutely no benefit to NOT spaying or neutering a dog undergoing
treatment. On the other hand, reproductive hormones in female dogs in
heat (estrus) or in pregnant dogs can cause worsening of the mites or
make it more difficult to control them. However, the presence of male
reproductive hormones (un-neutered males) makes no known difference in
the ability to control the Demodex mites. On a different note:
I do not treat dogs with localized demodicosis (less than six affected
spots) because more than 90% of them will resolve on their own. By treating
them, you will never know if the patient would have become a generalized
case or not.
QUESTION: Is Demodex transmissible to my healthy dog from
a dog that is infested?
ANSWER: Healthy dogs are quite resistant to infestations and,
as mentioned, may already have a number of mites residing harmlessly in
the skin. It is best, though, to not allow your dog to have direct
physical contact with a dog that has an active case of Demodex... just
to be safe.
QUESTION: What about the dog that suddenly develops Demodex
later in life and never had it as a puppy?
ANSWER: This is called Adult-onset Demodicosis and is most
commonly seen in what are assumed to be healthy dogs but that in reality
are actually affected with an underlying pathology or immune compromising
disorder. Therefore, whenever a veterinarian is presented with a case
of Demodex in an adult dog the doctor is alerted to the possibility that
there is a potentially serious underlying disease going on that has compromised
the dog's immune integrity. Such afflictions as cancer, Hypothyroidism, Systemic Fungal Disease,
Demodex mites usually create irregularly shaped, mildly irritated areas
of hair loss. The skin is usually not inflamed and the
The diagnosis is made by doing a skin scraping of the affected area
and placing the scrapings on a microscope slide. Click here to see how a skin
scraping is done. Usually the material scraped from the skin is mixed
with mineral oil and then examined under the microscope. (NOTE: Sarcoptic
mites are rarely visible via skin scrapings and are therefore very commonly
misdiagnosed as an allergic skin disorder because the veterinarian "couldn't
see any mites". See this article
for important information about Sarcoptic Mites.) Demodex mites are
plentiful and seem to be easily detected via skin scrapings even though
they spend most of their time deep in the hair follicles.
Human demodex cases are rather rare but do occur. It is believed
that demodex mites are a common residents of hair follicles in dogs
and humans, and when present in few numbers in a healthy individual seldom
cause clinically observable cases. Under certain unknown conditions,
though, humans can develop clinical cases of demodex mites. The images
below are of an animal caretaker who became infested in the facial regions
with demodex mites. She had been providing the dog with prescribed
treatments in the animal hospital. After consulting with a human dermatologist
she was eventually able to eliminate the mites but the process entailed
numerous topical treatments and also systemic medications. After
six months of treatment, all symptoms of the mites disappeared.
|Demodex in a human is presented. The Irish
Wolfhound in the image below-left had a resistant case of mites and therapy
covered many months before the dog was clear of any demodex parasites.
One of the many individuals who handled this dog one became infested with
the mites and displayed lesions on the face and neck. Therapy for
this individual took months before a successful resolution of the problem
was evident. Click on an image to enlarge.
In dogs with very mild, localized,
small skin lesions some veterinarians do not treat the dog at all.
Other veterinarians will always treat a Demodex lesion with topical medications
appropriate as an insecticide. (Some home remedies are harmful so
always consult with your veterinarian about any kind of skin lesion and
the safest and most effective therapy.) These organisms are live
parasites so applying such remedies as Vitamin E cream or aloe vera will
have no effect on them.
It is vitally important that all dogs (not just dogs with health problems)
be consuming a high quality,
meat-based diet with proper
amounts of high quality fat. Any dog, especially a growing pup,
that is consuming a cheap, grain-based diet will not fare as well as the
dog eating a high quality diet. In general, the better diets are
higher in price so do not let your decision about what to feed your dog
be dictated by the cost. The nutritional aspects of skin disorders
is an often overlooked "treatment" and should always be considered when a
health impacting situation is present. For good information about
nutrition, visit this department
for a list of articles.
Mitaban was a commonly used
treatment for Demodex and had a proven record of successes. This
prescription-only product is diluted with water and applied to the dog's
skin according to the product directions. Repeated applications are
almost always required. This product may no longer be available.
On occasion a veterinarian may decide to use a product called Ivermectin.
This product must be very carefully calculated regarding dosages that are
effective and not toxic. The use of Ivermectin in treating Demodex
needs to be discussed with the owner prior to use since it has not been
labeled for use against Demodex. Another treatment that is sometimes
used is oral milbemycin given daily for six to eight weeks. Lime-Sulphur
dips have been used in the past and some veterinarians continue to prefer
this therapy for demodex. Ivermectin in fairly high doses is also
used... with owner's consent and with caution!
|The dog in this image (a Doberman Pinscher)
was severely affected by Demodex skin mites from a very young age.
The entire dog was affected. After a year of intensive treatment with
dips, Revolution, Ivermectin, Mitaban, antibiotics, vitamins and other remedies,
the unfortunate dog was finally euthanized. No treatment or combination
of treatments had any affect on the state of the dog's health.
Dietary and alternative treatments were attempted but probably because of
genetically programmed immunity factors this patient was unable to ward
off the parasites and progress to healing.
sole property of ThePetCenter.com.
Any copying or reprinting of this material may be done only with verifiable
reprinted with kind permission from Dr Dunn
The above information is simply informational.
It's intent is not to replace the advice of a veterinarian nor to assist
you in making a diagnosis of your pet. Please consult with your own veterinarian
for confirmation of any diagnosis. Your pets life may depend on it.