Therapeutic considerations for mating-induced endometritis

A transient mating-induced endometritis is most likely physiological in the mare, serving to remove excess spermatozoa, seminal plasma, and contaminants from the uterus. However, the inflammatory reaction has to be resolved and inflammatory products cleared from the uterus prior to embryonal descent into the uterine lumen. Mares that fail to clear a semen-induced inflammation from the uterus develop a persistent mating-induced endometritis which may result in infertility. If susceptibility to persistent mating-induced endometritis is suspected, the mare should be monitored by transrectal ultrasonography for intrauterine fluid accumulation at 6-12 hours intervals after breeding. Treatment should be aimed at assisting the uterus to physically clear contaminants and inflammatory products. Post-mating uterine lavage and/or the use of uterotonic drugs are recommended at 6-12 hours after breeding in mares susceptible to persistent endometritis.