Comparative histomorphological study of endometrium in mares.

The research article examines the differences in endometrial histomorphometry in mares (female horses) and its connection with their susceptibility to endometritis, a type of inflammation of the uterus. The researchers found that mares with higher epithelial height, greater glandular density and more developed glands during their reproductive cycle were more susceptible to this inflammation.

Study Background and Objective

• The study seeks to understand the main pathological cause of subfertility in mares – persistent endometritis, an inflammation that occurs within 48 hours post-breeding. Mares can display different levels of resistance to this inflammation, and this resistance or susceptibility can influence their fertility.
• The aim was to identify differences in endometrial histomorphometry (the study of the microscopic structure of tissues) in mares during their respective oestrus (reproductive) cycles and to classify them as either susceptible or resistant to endometritis.

Methodology

• Endometrial biopsies were conducted on 24 mares during their oestrus phase. These samples were then subjected to Haematoxylin-Eosin staining – a common procedure for the microscopic examination of tissue samples.
• Variables such as the height of the lining and glandular epithelia, the perpendicular diameters of endometrial glands, and the number of endometrial glands per field were studied and compared between mares pre-classified as either susceptible or resistant to endometritis.

Results and Findings

• The characteristics of the endometrial tissue displayed differences between the two groups. Mares characterised as susceptible had higher lining and glandular epithelia, larger diameters of endometrial glands, and a larger number of glands per field compared to resistant mares.
• These results suggest a relationship between the histomorphometric characteristics of the mare’s endometrium and the susceptibility or resistance to post-breeding endometritis. Mares with increased epithelial height, greater glandular density, and an extensive development of the glands during the oestrus phase correlate with a higher susceptibility to endometritis.