The detection of Sarcoptes mites by means of skin scrapings can be tedious and is not always successful. Serology testing often presents a good alternative if the clinical symptoms are suspicious of sarcoptic mange. 25% of samples submitted to us for sarcoptes serology tested positive and about 13 % showed a questionable result. A questionable titer can result from either a low number of antibodies in the early stage of an infection or a reduction of antibodies after a successful therapy. Consequently serology testing can not be used for a therapy control. Theoretically questionable titers can originate from cross reactions with other mites.