Thursday, January 29, 2009
Skin mite Check
You will need a microscope, whether it be a cheap one from craigslist, a sophisticated one of your own, borrowing a vet's or schools scope, or in this case even a cheap kids scope will work. Get a few microscope slides and coverslips, they dont have to be fancy ones. You'll also need a small amount of mineral oil and a scalpel blade, both of these can be obtained at almost any feed store. Secure the animal you are doing the mite check on. For cattle or goats this might mean putting it in a stanchion, sheep you might set on their rear, Dogs you might have to have a buddy hold, cats you might need a cat bag (will cover cat bags in another post). Pick an area that hasn't been treated for the mite but is most likely to be infected, you will want to scrape the edges of an area since some mites do not like to live on the bare areas and will migrate to the edges. Put a drop of the mineral oil on the blade and gently pinch the area upwards between your fingers and scrape the area with the scalpel blade until it bleeds just a bit (surface bleeding not venous or arterial) then put a drop of mineral oil on the slide and stir whats on the blade around in it. Try to make it even height (not all the skin/debris piled up) and drop a coverslip on it. Then look at it under the microscope, 10X power. If there are mites there you will know, some look like weird shaped spiders others look like cigars...the different types look different but they all look like they don't belong with the rest of the stuff (skin cells, hair). The mites that burrow into the skin are harder to find and several scrapings may be required for those type of mites before you see them. The good news is that you can wash the coverslips and slide really carefully with soap and water and let them dry and can use them again and again. Cheyletidae, Chorioptes, and Psoroptes are all skin mites that live on the surface. Demodex and Sarcoptes burrow into the skin. Knemidokoptes is a burrowing mite resposible for scaly beaks in birds.