[Continuous examination of sows with cystic, degenerating ovaries using sonography and serum hormone determination]

Ten sows with cystic ovaries have been examined periodically by transrectal sonography (2 days intervals) and analysis of serum-progesterone and estradiol (7 days intervals). Estrus occurred in nine of the sows after a time up to 82 days. Estrus reappeared after an almost physiological interval of 22 to 24 days. The cysts on the ovaries regressed completely (4 sows) or diminished in size (5 sows) before estrus. The regression was preceded by increasing echoes from trabeculae-like structures in the cysts and increase of serum progesterone concentration. In six sows cysts were again detectable after estrus. These increased in size and regressed again in the same manner as before. All nine sows were served by a boar during second estrus and seven became pregnant according to sonographic findings after 27 days. These results show that sows with cysts on there ovaries may maintain an ovarian cycle and even conceive. The regression of ovarian cysts is probably preceded by the formation of luteal tissue. Our results don't allow general conclusions concerning the role of ovarian cysts in sows as a cause of infertility due to the small number and the unknown anamnesis of our patients. However in only one of the ten sows, the cysts persistent beyond the observation time of 100 days.