Videoendoscopic evaluation of the mare's uterus: II. Findings in subfertile mares.

Videoendoscopy of the reproductive tract was performed in 87 Thoroughbred mares with histories of reduced fertility. During hysteroscopy samples for cytological, microbiological and histological examinations were obtained under visual control. Common findings in these broodmares included: (a) endometrial degeneration, as assessed by an uneven distribution or atrophy of endometrial folds and/or a scarred appearance of the endometrium (49 mares, 56%); (b) endometrial cysts of various sizes and locations within the uterus with the most common location being at the base of the uterine horns (48 mares, 55%); (c) fluid accumulation in the uterine lumen (28 mares, 32%). A few mares had transluminal adhesions (7 mares, 8%) and in 2 mares the adhesions appeared to obstruct one uterine horn completely. A solitary discrete lump was detected in the wall of the uterine body in one mare and the suspicion of it being a leiomyoma was confirmed histologically with the aid of a visually directed biopsy sample. Free intraluminal structures were present in the uterine lumen in 3 mares, including one inspissated blood clot and two suspected remnants of resorbing pregnancies. Flexible biopsy forceps and scissors passed through the working channel of the endoscope were used to sever small thin adhesions, but this method proved inadequate for multiple adhesions or cysts. Solitary endometrial cysts were removed by means of conventional rigid biopsy forceps passed alongside the endoscope, although bleeding from the operation site usually limited this type of intervention.