Why bother checking stool samples at all?
Firstly, stool samples are performed to help assess the success of deworming treatments of confirmed cases.
Stool checks are also required routinely to check for the other parasites that are not treated by the standard deworming treatment (Giardia, Coccidia, Tapeworms, etc.), and to check for more unusual parasites (Physaloptera, Paragonimus, Alaria).
Skin parasites (Sarcoptes, Demodex mites) may show on stool samples, after pets chew their itchy skin and swallow the microscopic mites. This is an unexpected but effective means of diagnosing skin mites.