Endometrial biopsy sampling interpretation findings in the diagnosis of subfertile mares in the veterinary practice

Background: Non-pregnant, subfertile broodmares cause a significant expense in horse breeding. Beyond the routine physical and sonographic examination, advanced techniques are available for diagnosing subfertility (microbiology, endometrial biopsy) in mares. For detecting inflammatory and degenerative changes of the endometrium, histopathologic studies have been investigated the possible causes of sub/infertility. Objectives: The aim of the authors was to summarize the available information about the usefulness of endometrial biopsy sampling in mares in connection with barrenness. Furthermore, a special attention has been paid to the recently discovered investments in the diagnosis of endometrial problems in the mare. Material and method: Review and study papers have been summarized with the aim of scientific databases (www.sciencedirect.com; www.pubmed.com) from 1978 until 2017. The following keywords have been used: endometrial biopsy, mare, barren mares, endometritis, endometrosis (endometriosis), fibrosis. Results and discussion: According to our experience and the available veterinary literature, in case of infertility/subfertility of broodmares of high value, the use of advanced examination techniques is suggested in order to detect subclinical diseases; however, a single examination is not sufficiently enough to estimate the fertility of a broodmare.