The effect of age and parity on the development of equine chronic endometrial disease.

This research delves into the relationship between a mare’s age, her offspring count, and the severity of chronic degenerative endometrial disease (CDE). The study found a significant link between the horse’s age and the onset of this disease, with severity increasing with age, but found minimal or non-practical correlations with other factors investigated, such as the number of foals delivered or years spent barren.

Understanding the Research

• The research team carried out a retrospective analysis. This means that they looked back on pre-existing data rather than setting up a new experiment. In this case, they used 3,804 endometrial biopsy specimens, which were collected from non-pregnant mares during routine check-ups at a stud farm.
• The main focus of the paper was to understand the relationships between the severity of chronic degenerative endometrial disease (CDE), the age of the mare, her number of offspring (parity), and any barren years prior to the biopsy.
• CDE is a disease characterized by the degeneration of the inner lining of a mare’s uterus. This can lead to fertility issues and is therefore important to understand and manage in breeding mares.

Key Findings

• The researchers found a significant correlation between a mare’s age at the time of examination and the severity of CDE diagnosed. This indicates that older mares were more prone to severe cases of CDE.
• However, the correlations between the severity of CDE, the number of foals born, and the number of barren years leading up to the biopsy were not significant enough to be practically useful. This suggests that the age of the mare was a more influential factor than her breeding history when it came to the severity of CDE.
• Despite examining the correlation between chronic infiltrative endometritis (CIE) – a specific type of inflammation of the uterine lining – and a horse’s age or pre-biopsy offspring count, these relations were found to be minimal.

Conclusions and Future Implications

• Based on their findings, the researchers proposed age-based guidelines for diagnosing the severity of CDE in mares. This included suggestions that mares up to nine years old should not show signs of CDE, and that severity should increase with age, with mares over 17 years old likely to exhibit severe signs.
• They felt these guidelines could help assess a mare’s breeding prognosis, providing an objective tool for managing and predicting her reproductive health. It could also help take proactive steps in preventing or managing CDE in older mares.
• The lack of significant correlations regarding breeding history suggest that other, yet unexplored, factors might influence the development of CDE, providing potential avenues for future research.