Diagnostic hysteroscopy in the mare - uterine contamination and endometrial reaction

Despite the fact that, nowadays, hysteroscopy is performed routinely, in eq uine gynecology, for diagnostic and minimally invasive surgical treatment, certain aspects should be considered in order to gain optimal conditions an d results for the mare and for those carrying out the examination. These in clude thorough ascertainment of indication, careful uterine distension, cho ice of the correct stage of cycle and establishment of an adequate follow-u p treatment and management. In order to monitor possible changes in the hea lth of the genital tract following diagnostic hysteroscopy the clinical, mi crobiological (uterine swab) and pathohistological (endometrial biopsy) sta te of eight diestrous mares were examined before performance of a hysterosc opy, five days later and after the estrus which followed. Uterine distensio n was established by insufflation of filtered air. No follow-up treatment w as carried out. At the outset all eight mares were clinically healthy, without evidence of pathogenic microbes in the uterine swabs or inflammatory alterations in the endometrial samples. Five days after hysteroscopy pathogenic microbes were detected in 50% of th e mares (in three cases: slight amount of Pseudomonas aeruginosa, in one ca se: moderate amount of E.coli and slight amount of beta -haemolytic Strepto coccus). This last mare revealed a clinically discernable endometritis. End ometrial biopsy enabled a diagnosis of moderate, acute, superficial endomet ritis in this mare. A further five of the eight mares developed slight acut e inflammatory endometrial reaction which was only detected through pathohi stology, though only two of them showed the presence of pathogenic microbes . Following the subsequent estrus all mares were clinically healthy. In two m ares Pseudomonas aeruginosa persisted, the others were not contaminated wit h pathogenic microbes. Two further mares still showed slight, acute, inflammatory endometrial reac tions. A remarkable finding in the endometrial biopsies was the striking rise in t he number of eosinocytes in the superficial layers of the endometrium five days after hysteroscopy, seen in six of eight mares. After the following es trus the number of eosinocytes was still obviously elevated in four mares. A contamination rate of 50% shows that a prevention of endometrial infectio n is indicated after hysteroscopy, for example through the infusion of mild antiseptic solutions into the uterus. Additional induction of estrus can a dvance uterine clearance. Independent of intrauterine contamination, 75% of the mares showed inflamma tory endometrial reactions on pathohistology. It might therefore be recomme ndable not to use the following estrus for insemination. The aetiology of the endometrial eosinophilia following Uterine distension through insufflation of filtered air is to date unknown. A correlation betw een poor vulvovestibular conformation and eosinophilic infiltration of the endometrium has been established by other authors in the post and a connect ion here seems likely.