SARCOPTIC MITES and DEMODEX MITES are often referred to as MANGE. The word mangy describes a ragged and uneven hair coat and damaged skin that results from mites affecting the skin and hair follicles. Mange is responsible for many annoying and persistent problems in veterinary dermatology. (Demodex) http://www.thepetcenter.com/exa/dem.html mites in general are less troublesome than Sarcoptic mites, cause less itching and self-mutilation, and are not seen in adult dogs as often as Sarcoptic mites. The mite known as SCABIES, SARCOPTIC MITES or SARCOPTIC MANGE are highly communicable little bugs that actually dig tiny tunnels into the skin where they cause intense itching, inflammation and hair loss. Many, many cases of skin itching (called “pruritus”) in dogs and cats have been diagnosed by veterinarians as “Allergic Dermatitis” when in fact the pet had sarcoptic mites. (See the article called (ITCH AND SCRATCH) http://www.thepetcenter.com/gen/itch.html). The difficulty lies in the fact that Sarcoptic Mite infestation really does look like an allergic dermatitis because the skin is reacting to an irritant... just like an allergy! The intense itching results in self trauma, hair loss, and dry crusty skin lesions. In some cases the dog or cat can lose large areas of fur and literally be covered with crusts and scabs. Scabies mites can affect humans, as well. A swift diagnosis of sarcoptic mites is vital to the pet’s health and the well being of the pet’s owner. Generally, in healthy humans who are not immune suppressed, the Scabies Mites do not reproduce very readily and may simply “go away” without medical treatment. If you are in doubt about human cases of Scabies, consult your physician.
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A SIMPLE WAY TO
PRESUME THE DIAGNOSIS OF SCABIES IN DOGS
Scroll down to see a movie of the
Pinna-Pedal Reflex
In over 95% of dogs
with Sarcoptic Mite infestation (Scabies) a simple test can suggest that
these mites are present. It is called the Pedal-Pinna Reflex
Test. Since almost all dogs with Scabies mites will have mites
along the ear flap (called the Pinna) margins, as displayed
in some of the photos below, the dog will reflexively use a back leg in
a scratching motion if the Pinna is scratched gently by a person testing
this reflex. Simply take the Pinna between your thumb and
forefinger and vigorously scratch the surface of the underside of
the Pinna with the forefinger. Dogs with no mites seldom work the
back leg in a scratching motion. Dogs with sarcoptic mites almost
always will demonstrate an involuntary scratching motion with the back
leg while you are scratching the Pinna. |
A further unfortunate happenstance with the misdiagnosis is that far too often veterinarians will quickly reach for the cortisone, for example Prednisone, as a way of combating the effects of the “Allergic Dermatitis”. The cortisone is not a cure... it simply lessens the itching and scratching and the dog or cat feels more comfortable. The danger here is that IF the pet really has scabies mites and NOT an allergic dermatitis, the mites welcome the cortisone with open arms... er, ah... I mean legs! And they have eight of ‘em! The cortisone allows the sarcoptic mites to reproduce more rapidly and decreases the dog or cat’s ability to defend against the mites. The mites have a reproductive festival after cortisone products are administered
And here’s another problem... sarcoptic mites are very elusive. Ordinarily, skin scrapings are utilized to pick up mites from the skin, a few drops of solution is applied to the scraping and the substance is examined under the microscope for the presence of mites. Cheyletiella are easy to find, (Demodex) http://www.thepetcenter.com/exa/dem.html are easy to find, ear mites are easy to find... scabies mites seldom are found. Take as many scrapings as you like, even go deep into the skin, and the odds are that you still will not find the scabies mites. This has led many an unwary veterinarian down the road to misdiagnosis. After all, if no mites are found on this itchy, inflamed pet with hair loss and skin sores, it must be an allergic dermatitis, right?
Some veterinary schools who accept referrals to their dermatology specialists will not accept a pet for allergy testing until a trial treatment of Ivermectin medication is used first. Then, if the pet is still itching and scratching after a few weeks trial period, they will consider examination the dog or cat for allergy testing and treatment. That’s how common it is for Sarcoptic mites to be mistaken for Allergic Dermatitis... the specialists want mites to be ruled out first before they begin allergy testing. There is a new product, described below, available to your veterinarian from Pfizer Animal Health that may be an excellent medication for the treatment of Sarcoptic Mites.
What is Ivermectin?
| NOTE:
Some veterinarians believe that Ivermectin should NOT be used in Collies, Shelties
and other herding breeds. Thoroughly discuss the use of Ivermectin in
herding breeds with the veterinarian before using this product in these
breeds and consider alternate therapies if there is any uncertainty
regarding the safety issue. |
This amazing chemical has been used for years as a large animal (farm animal) dewormer. It is also the active ingredient in the famous Heartworm preventative called Heartgard. Scientists and practitioners found out that if used IN THE CORRECT DOSE, Ivermectin, either injected or given orally, can kill sarcoptic mites! This is a fabulous discovery since dogs no longer have to endure chemical dips and sprays to eliminate scabies mites. The Ivermectin, IN THE CORRECT DOSE, can successfully treat dogs for sarcoptic mites.
Now... here’s the downside: Some dogs have a genetically determined sensitivity to Ivermectin!
FROM THE WASHI8NGTON STATE UNIVERSITY VETERINARY SCHOOL website: It is well known that Collies and related breeds can have adverse reactions to drugs such as ivermectin, loperamide (Imodium®), and others. It was previously unknown why some individual dogs were sensitive and others were not. Advances in molecular biology at the Veterinary Clinical Pharmacology Laboratory at Washington State University's College of Veterinary Medicine have led to the discovery of the cause of multi-drug sensitivity in affected dogs. The problem is due to a mutation in the multi-drug resistance gene (MDR1). This gene encodes a protein, P-glycoprotein, that is responsible for pumping many drugs and other toxins out of the brain. Dogs with the mutant gene can not pump some drugs out of the brain as a normal dog would, which may result in abnormal neurologic signs. The result may be an illness requiring an extended hospital stay--or even death.
A test has recently been developed at Washington State University to screen for the presence of the mutant gene*. Instead of avoiding drugs such as ivermectin in known susceptible breeds, veterinarians can now determine if a dog is normal, in which case the drug can be administered or abnormal, in which case an alternative treatment can be given. Owners and breeders can submit samples for testing. All that is needed for the test is a cheek brush sample that can be obtained by the owner and sent by mail for analysis.
Affected Breeds
Approximately 3 of every 4 Collies in the United States have the mutant MDR1 gene. The frequency is about the same in France and Australia, so it is likely that most Collies worldwide have the mutation. The MDR1 mutation has also been found in Shetland Sheepdogs (Shelties). Australian Shepherds, Old English Sheepdogs, German Shepherds, Long-haired Whippets, Silken Windhounds, and a variety of mixed breed dogs.
The only way to know if an individual dog has the mutant MDR1 gene is to have the dog tested. As more dogs are tested, more breeds will probably be added to the list of affected breeds.
Ivermectin is not approved to be used in this manner. So your veterinarian should let you know this prior to getting your permission to utilize Ivermectin therapy in the treatment of scabies in dogs and cats. You can retain some confidence to know that it is in common usage, and has been for a number of years, for the treatment of scabies in pets. It simply has not been tested by the manufacturer and approved by the FDA to be used in this manner. You are on your own, you and your veterinarian, in the decision-making arena regarding whether or not to use it to treat sarcoptic mites. Your alternative is to use insecticide dips and sprays. Additionally, if the wrong dosage is given, the pet can have a very serious and even fatal reaction to Ivermectin. The correct dose MUST be given and great care taken not to give too much.
All pets in contact with an affected animal should be treated since there can be asymptomatic carriers (they have the disorder but aren’t showing any signs of disease) of the sarcoptic mites. Pfizer Animal Health has released a new product called Revolution that is approved for use on dogs for the elimination of Sarcoptic mites. Be sure to ask your veterinarian about this.
There are a number of treatments available to eliminate Sarcoptic Mites from dogs and the veterinarian will decide which may be best for each individual case. All dogs with scabies mites need to be on a high quality, meat-based diet... and many will benefit from supplements such as Vitamins and Fatty acids. See PetFoodDirect.com for home delivery of skin specific supplements and Vitamins... plus an excellent breakdown of many pet diets and their ingredient lists.
If your dog is being treated over and over (unsuccessfully) for "allergies" with cortisone products and has never had Sarcoptic Mites actually ruled out as a possible cause of the skin condition, ask your veterinarian about the advisability of a trial treatment for scabies... just in case.
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Click to enlarge the
images below that show actual cases of sarcoptic mites |
Scabies
on the elbow of a dog |
View a
movie of the PINNA-PEDAL Reflex...
a way to make a presumptive diagnosis of
Sarcoptic Mites in a dog
By
scratching at the edges of the pinna margins (ear flap edges), the doctor is
able to elicit a reflex scratching motion... mites are highly likely! |
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Double-click on
the left button to see a movie of a dog with sarcoptic mites.
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Same
patient, more skin lesions |