Uterine contractility is necessary for the clearance of intrauterine fluid but not bacteria after bacterial infusion in the mare.

The research paper investigates how uterine contractility in mares affects the clearance of intrauterine fluid and bacteria, finding that uterine contractility plays a significant role in clearing fluid but not necessarily in eliminating bacteria after bacterial infusion.

Research Methodology

• The research was conducted on 5 estrous mares. These mares were chosen as they were resistant to persistent mating-induced endometritis – inflammation of the uterine lining often caused by infection after mating or childbirth.
• Firstly, bacteria were infused into the uteri of these mares during a control cycle.
• Subsequently, the same process was repeated but during this second round, the mares were also treated with clenbuterol. Clenbuterol is a beta 2 agonist which is known to reduce uterine contractions.

Data Collection

• After 48 hours of bacterial infusion, uterine cellular responses were evaluated through transrectal ultrasonography and uterine lavage – a process where the uterus is washed out with fluid.
• Data was collected which included: the degree of fluid accumulation in the uterus, the cloudiness of lavage fluid, the number of cells per milliliter, the percentage of neutrophils – cells that form an essential part of the immune system – and the frequency of bacterial growth from the recovered fluid.

Findings and Conclusion

• During the cycle when the mares were given clenbuterol, all of them accumulated intrauterine fluid. In the control cycle where no clenbuterol was given, none of the mares retained fluid.
• No significant difference was recorded between the two cycles with regards to the cloudiness of lavage fluid, number of cells per milliliter, percentage of neutrophils, and frequency of bacterial growth.
• The study concluded that uterine contractility is significant for the clearance of uterine fluid, but not necessarily for eliminating bacteria.
• These findings support previous evidence suggesting that impaired uterine contractility plays a role in the development of persistent mating-induced endometritis.