A skin scraping is a diagnostic test used in almost every skin condition. An important use of this test is to detect mites, which are microscopic in size. Mites are far too small to be seen with the naked eye, and can only be positively diagnosed by a skin scraping and subsequent analysis of the scraped material under the microscope. The two mites we commonly diagnose by a skin scraping are Sarcoptic mange (Scabies) and Demodex.
Mites burrow into the skin or hair follicles, some burrowing deeper than others. Sometimes we need to perform several scrapings at various locations in order to find mites. Some mites have a propensity to affect certain areas, so these are the areas we emphasize when we perform the test. A negative skin scraping does not guarantee your pet is free of mites. Demodex mites are relatively easy to find under the microscope, while Scabies (Sarcoptes) mites can be very difficult to find under the microscope.
Obtaining a Sample
The first step is to gently scrape the surface of the skin with a scalpel blade. This will yield skin, hair, dander and sometimes the mites if they are present.
When the scraping is performed properly there will be a small irritated area on the skin. This signifies that the scraping was done thorough enough to find mites that burrow deep. The minor irritation will resolve in a short time and does not need any medication.
The scraped material is transferred to a slide for viewing under the microscope. The slide is methodically analyzed for mites, mite eggs, or evidence of a fungal infection. This takes 5 minutes, so the report is available while you wait.