Identifying demodex vs sarcoptes mange mites

To do a skin scraping you need:

• a dulled scalpel blade or other instrument for scraping
• a slide
• mineral oil
• a microscope

1. Put a drop of mineral oil on the slide and dip the blade or scraper in the oil to lightly coat it so that the debris will stick to the blade.
2. Choose an area of alopecia and scrape the skin with the blade until you begin to see blood.  This is necessary because demodex mites live in hair follicles which are fairly deep under the surface of the skin.  (Some say to pinch the skin while scraping it, but I've never seen this done in practice.)
3. Clean debris off of the blade by dipping it in the mineral oil and wiping it off on the slide -do the best you can.  
4. Repeat the procedure using 3-5 different sites.  This is important because sarcoptes (scabies) mites are hard to find.

When finished, view the slides under low (10X or "scanning") power and look for mites.  Medium power may be used if you are not used to looking for mites.  (Medium power will give you a field of view closer to the photos below.)

Demodex mites are most commonly found because a small number live on pets normally, but an abnormal immune response can cause these mites' numbers to increase enough to cause clinical signs and require treatment.  Usually these clinical signs are hair loss with or without itching that can lead to pyoderma and other secondary skin infections.  It can occur locally, usually on the face or forelimbs and paws, or be generalized.

Some say demodex mites look like cigars.  They are elongated and have eight legs that you may see moving on the front half of their body.

If demodex (demodectic mange) is diagnosed it should be noted that it is NOT contagious to humans or other pets in the household.


Sarcoptes mites are round, on the other hand, so they are easy to distinguish from demodex:

If sarcoptic mange is diagnosed it should be noted that it IS contagious to other pets who come in contact with the infected pet as well as humans.  So, wash your hands thoroughly after handling animals with sarcoptic mange or, better yet, wear gloves and protective clothing if it is suspected.

Clinical signs of sarcoptic mange is intense pruritis (itchiness) and hair loss that begins on the ventral abdomen, chest, ears, elbows, and legs and, if left untreated, can become generalized.