Читать книгу Practical Equine Dermatology - David H. Lloyd - Страница 19

Skin scrapings can be performed for detection of external parasitic diseases such as chorioptic mange, larval stages of harvest mites, demodicosis (rare), or for dermatophyte culture and cytology.

 If necessary, remove hair over areas to be sampled by careful clipping.

 Use a wooden tongue depressor for superficial sampling or a large, curved scalpel blade if deeper samples are required, with the sharp edge blunted to reduce the risk of injuring the horse or operator.

 Moisten the sample site or the collection tool with liquid paraffin (more useful for examination for mites), water or normal saline (for dermatophytes).

 Gently scrape crusts, scales, and associated hair so that the material accumulates on the blade or tongue depressor. Transfer onto a microscope slide with more liquid paraffin, or with potassium hydroxide solution if collected in aqueous medium, which allows clearing of debris and easier identification of pathogens.

 Deeper scrapings are needed for suspected demodicosis, deep enough to cause capillary ooze.

 Sample several sites, collect plenty of material, and divide amongst several slides to make thin suspensions, which are quicker and easier to examine efficiently.