Retrospective study on vulvar conformation in relation to endometrial cytology and fertility in thoroughbred mares.

The study looked at the link between the shape of a horse’s vulva and its risk of uterine infection and fertility. It found that certain changes in vulva shape can increase the risk of infection, which in turn can affect a horse’s fertility. The study also found that surgical procedures to adjust the vulva shape can improve fertility.

Objective of the Study

• The main goal of this study was to examine the relationship between the status of the mare’s vulva (whether it had been previously operated on or not, and whether it was resutured after giving birth), endometrial cytology, conception rates, and live foal rates in different age groups and categories of thoroughbred mares.

Methodology

• The researchers carried out a thorough examination of the vulvar area of the mares, and also took endometrial samples for bacteriological and cytological analysis.
• All mares were mated naturally, once during their oestrus cycle, by one of two stallions.
• The study did not allow mating during foal heat.

Findings

• Mares with vulvar status group A (non-operated) had the highest conception rate and live foal rate, compared to those with vulva status group C (those previously operated and/or not resutured after the last birth).
• The analysis showed that the vulvar status upon arrival had a significant impact on the pregnancy rate and live foal rate, but did not have an effect on fetal loss. Other factors, like the stallion involved, the year of the study, and age group of the mares, did not have any significant effect on the variables that were analyzed.

Conclusion

• The study concluded that by carefully managing factors such as resuturing mares immediately after birth if they had been operated on (Caslick operation), the growth of harmful microorganisms which could cause endometritis might be minimized. This, in turn, could improve conception rates and the mare’s ability to carry a pregnancy to term.