Evaluation the prevalence of persistent post-mating endometritis in Arabian mares

The incidence of persistent post-mating endometritis (PPME) following natural mating or artificial insemination (AI) is always underestimated in mares that do not have abnormal clinical signs in reproductive tracts in routine examinations before mating in high-population horse breeding centers. In this study, 503 Arabian mares whose reproductive system status was confirmed before natural mating or artificial insemination in breeding soundness examination, were examined with ultrasonography at 24, 48, and 72 hours after ovulation, in terms of PPME following natural mating or AI, and the presence of uterine fluid accumulation with a diameter of 5 mm or more is recorded as PPME. The correlation between PPME and other variables such as age, type of mating, number of mattings in an estrous cycle, pre-ovulatory follicle (POF) size, volume and concentration of semen used in AI was investigated at different time intervals after ovulation. The results of this study showed that, the incidence rate of PPME following natural mating or AI in 48 and 72 hours after ovulation is 32 and 22%, respectively, in a normal population of Arab mares. Based on this rate, reproductive examinations are recommended 24 and 48 hours after ovulation in the group of sensitive Arab mares.