Assessment of Connective Tissue in the Equine Uterus and Cervix: Review of Clinical Impact and Staining Options.
Authors: Zdrojkowski Łukasz, Pawliński Bartosz, Skierbiszewska Katarzyna, Jasiński Tomasz, Domino Małgorzata
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Uterine disease remains the leading cause of infertility in mares, yet routine diagnostic biopsies typically rely solely on standard haematoxylin-eosin staining, which provides limited visualisation of connective tissue pathology. This 2024 review examines how specialised histological stains—including Masson trichrome, picrosirius red, elastica van Gieson, and periodic acid-Schiff—can substantially improve diagnostic capability when evaluating endometrial and cervical samples. The authors highlight that vascular changes and fibrotic remodelling are particularly prevalent in multiparous mares and directly impact early gestation and placental development, yet these features remain underdiagnosed using conventional staining protocols. Since equine endometriosis is predominantly characterised by endometrial fibrosis, and given the subjective nature of fertility-related pathology assessment, the adoption of specialised connective tissue stains could provide more objective and clinically relevant diagnostic information. For equine practitioners, this suggests that requesting targeted histological analysis rather than standard staining alone may improve diagnostic accuracy and help identify subtle uterine pathology that would otherwise be overlooked, ultimately supporting more informed fertility prognosis.
Read the full abstract on PubMed
Practical Takeaways
- •Request special connective tissue stains alongside routine H&E staining when submitting endometrial biopsies for fertility evaluation—this significantly improves diagnostic accuracy for detecting fibrosis and vascular changes.
- •Understand that standard H&E staining alone may miss important pathological changes in mares with repeated breeding failures; advocate for enhanced staining protocols with your diagnostic laboratory.
- •Recognize that multiparous mares are at higher risk for uterine vascular and fibrotic changes; consider more thorough histological evaluation in older mares with declining fertility.
Key Findings
- •Uterine diseases are the primary cause of infertility in mares, yet diagnosis often relies solely on hematoxylin-eosin staining which may miss important connective tissue changes.
- •Special stains (Masson trichrome, picrosirius red, elastica van Gieson, periodic acid-Schiff) enhance visualization of connective tissue pathology and diagnostic accuracy in endometrial samples.
- •Vascular changes and fibrotic alterations are particularly prevalent in multiparous mares and directly impact placental development and early gestation.
- •Equine endometriosis is predominantly associated with endometrial fibrosis, and connective tissue stains are currently underutilized in routine diagnostic histopathology.