Clitoral anatomy and sampling the clitoral sinuses
Keywords: equine, clitoris, CEM
Clitoral sinuses are routinely cultured for the CEM organism or CEMO, Taylorella equigenitalis which is able to grow in this relatively anaerobic environment. Image A shows the location of one of the largest clitoral sinuses; usually the central sinus on the dorsal surface of the clitoris.
Image size: 2000 x 1207px
Image B shows the approximate depth of the largest sinus, certainly deep enough for an anaerobic environment. The inset between images A and B shows that this central sinus can even stretch and harbor large amounts of smegma. This mass of accumulated smegma is analogous to a “bean” found in a preputial diverticulum in a stallion. In this case, the smegma contents of the sinus have been cleaned out by squeezing the margins of the clitoris. The smegma itself probably provides an anaerobic environment for the growth of Taylorella equigenitalis.
Due to the small size of the clitoral sinuses, it is best to use small diameter swabs to culture for CEM. A conventional swab with a blue cap is shown next to a narrow bore swab that is ideal for sampling the clitoris. In the inset image at top left, it is apparent that a large swab cannot easily fit into a clitoral sinus.
