Diagnosis of equine endometritis

Introduction Diagnosis of infertility problems in the mare by sampling of material from the uterus was first described more than 85 years ago in Kentucky, USA and Germany (1,2). Uterine disease, primarily endometritis, is still one of the major causes for infertility in the mare and a substantial problem in the modern breeding industry (3). Uterine samples have mainly been used to diagnose infertility problems and endometritis by bacterial culture (4,5), cytology (6,5), and histology (7). The finding of polymorph nuclear cells (PMN ́s) in a sample demonstrates the presence of endometrial inflammation, but without identification of the cause, it often is not possible to propose an optimal treatment protocol (4). A more differentiated diagnosis of both inflammatory and degenerative causes for endometritis and endometriosis can be obtained by a histological examination of an endometrial biopsy (7). The severity of the endometrial inflammation and degeneration found is correlated to the chance of the uterus to support an established pregnancy to term (7). Originally material from the uterus for bacteriological and cytological examination was proposed collected through a vaginal speculum using a sterile cotton swab (1,2,4). In recent years however, alternatives to the guarded swab for collection of material from the equine endometrium have been proposed, and the sensitivity and specificity of these diagnostic tests have been evaluated and compared with established techniques (9,10). These methods include bacteriology and cytology obtained from double guarded swabs, cytological brushes, endometrial biopsies and endometrial flushings with sterile 0.9 % saline solution.