Download Demodectic Mange Information

Demodectic Mange Information from Your Veterinarian in McKinney
By Dr. Ed Mapes
One type of mange we see more often than others is caused by a mite called Demodex
folliculorum. This is a microscopic insect that lives in the hair follicles and causes hair
loss in dogs.
This usually occurs in young dogs, often puppies. It is thought that their immune
systems fail to suppress the mites, allowing them to exist and produce
symptoms. Short-haired breeds are most commonly affected: Dachshunds, Pit Bulls,
and Boxers are the most frequent patients with this mange.
The dogs are often unaware of the lesions, since there is usually no itch associated
unless a bacterial infection arises secondarily. We see patchy hairless areas of the
front legs, face and head, and shoulder areas; but cases can become generalized and
involve most of the body.
The more severe cases involve skin inflammation and infection, extensive hair loss,
thickening of the skin, and the dogs can run fevers and become lethargic. These dogs
will begin to scratch at the inflamed skin.
We diagnose Demodex by using a test known as a skin scraping. Hair is clipped from
around the suspected lesion, and then we squeeze the skin to force mites closer to the
surface. Using a surgical scalpel, we then carefully scrape the skin to remove the top
layers of dermis.
The scraped material is placed on a microscope slide, and we scan to identify the
insects. They resemble submarines with legs and mouth parts at one end – the legs
and head are usually still moving. It is interesting to bring pet owners into the lab area,
where we transmit the microscopic image to the computer for viewing; people are
usually surprised at the appearance of the mites.
Treatment of Demodectic mange depends on whether the condition consists of only a
few lesions or a more serious generalized case. Ivermectin is a drug used to kill the
mites, but we are very careful to control the dosage to prevent side effects. The
schedule calls for very low doses initially, gradually increasing for a more potent effect.
Side effects in dogs include:
 vomiting
 dilated pupils
 muscle tremors
 blindness
 incoordination
 lethargy
 lack of appetite
 dehydration
I have never seen adverse reactions when pet owners stick to the prescribed schedule
of administration. We recheck patients after two weeks to monitor progress and
prescribe dosing for the next two weeks. This continues until we’ve had two skin
scrapings with negative results.
Medications used in conjunction with Ivermectin include antibiotics, medicated
shampoos, and omega-3 fatty acids. There is often a noticeable improvement within
the first two weeks of therapy, but complicated cases can involve weeks of
treatment. Patients usually re-grow hair in affected regions after the mites are
eradicated, and there should be no permanent scarring of the skin.
Pet owners are advised to have any pets displaying small areas of hair loss examined
by a veterinarian in McKinney TX. Demodex, and other forms of mange as well, are
easier to treat when we make early diagnoses.