The Healthy and Diseased Equine Endometrium: A Review of Morphological Features and Molecular Analyses.
Authors: Schöniger Sandra, Schoon Heinz-Adolf
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary The equine endometrium is prone to multiple pathological conditions—including endometrosis, nonsuppurative endometritis, glandular maldifferentiation, and angiosis—that significantly compromise fertility and represent a considerable economic burden to the breeding industry. Schöniger and Schoon's comprehensive review synthesises morphological and molecular evidence from the literature to characterise how these subclinical diseases develop and progress, emphasising that most endometrial pathologies cannot be detected clinically and require histopathological examination of biopsies for reliable diagnosis. Key findings highlight that endometrosis involves characteristic periglandular fibrosis whilst nonsuppurative endometritis is distinguished by stromal infiltration of lymphocytes and plasma cells; importantly, the underlying mechanisms driving these conditions remain poorly understood, though some mares demonstrate predisposition to persistent infection through likely multifactorial pathways. The review identifies alterations in expression of cellular and molecular markers—both within and outside endometrial cells—as potentially useful diagnostic biomarkers that could improve detection of subclinical disease and inform targeted treatment strategies. For equine practitioners, this consolidation of morphological and molecular data underscores the diagnostic limitations of clinical examination alone and highlights the value of endometrial biopsy combined with advanced molecular profiling to optimise reproductive management, particularly in mares with subfertility or breeding histories suggestive of endometrial involvement.
Read the full abstract on PubMed
Practical Takeaways
- •Endometrial disease is a major cause of subfertility in mares with significant economic impact on breeding operations; subclinical forms require biopsy for diagnosis
- •Glandular differentiation assessment must account for seasonal variation in the equine endometrium
- •Emerging molecular biomarkers may improve diagnostic accuracy and treatment decisions, though further validation for clinical use is needed
Key Findings
- •Endometrial diseases in mares are predominantly subclinical and require endometrial biopsy and microscopic examination for diagnosis except in suppurative cases
- •Endometrosis is characterized by periglandular fibrosis while nonsuppurative endometritis shows stromal infiltration with lymphocytes and plasma cells
- •Persistent endometritis in some mares has a multifactorial etiology and pathogenesis of endometrosis and nonsuppurative endometritis remains undetermined
- •Alterations in intra- and extracellular molecular markers are associated with endometrial disease and may serve as diagnostic biomarkers for equine endometrial health