Morphology of the female reproductive organs of the African lion (Panthera leo)

Abstract

The objectivie of this study was to describe the splanchnology and topography of the female reproductive organs of the African lion. The reproductive organs of three embalmed cadavers from three-year-old known aged nulliparous lionesses weighing between 120 kg and 140 kg were studied. Two fresh carcasses from another study were used for some of the topographical photos since these rendered better quality images. The project was approved by the Animal Use and Care Committee and Research Committee of the University of Pretoria (protocol number V038-09). The topography and splanchnology of the reproductive organs were studied and described in situ and after removal. The kidneys were located far caudally in relation to the thirteenth ribs with the left kidney further caudal. The suspensory ligament was very well developed. It originated in a fan-like manner from the dorso-lateral abdominal wall lateral to the kidney extending up to a few centimetres cranial to the kidney. The proper ligament of the ovary was well developed and consisted of several clearly distinguishable bands. The broad ligament resembled that of the cat with the exeption of the cranial part of the mesovarium being very well developed. The round ligament was well developed and inserted on the medial femoral fascia. It therefore did not extend to the vulva as in other canine and feline species. The left ovary was longer, wider and heavier than its right counterpart and the ovaries were relatively small in relation to body weight. The ovarian bursa had a short mesosalpinx that did not cover any part of the ovary and the fimbriae extended the entire length of the ovary. The urethral tuberculum as well as the urethral crest was very well developed. The left uterine horn was longer than the right and the tip of the uterine horn was located dorsal to the proper ligament. The uterine tube was prominently convoluted, situated entirely on the lateral aspect of the ovary and was found to open directly into the tip of the uterine horn and not onto a papilla. The female reproductive organs of the African lion resemble that of the domestic cat and dog with some major differences especially to the size and development of certain structures. The clinical relevance of these differences has to be debated and some thoughts might include the following: 1) does the suspensory and proper ligaments of the gravid uterus contract to suspend the entire uterus closer to the body wall during hunting since the lioness is the primary hunter in the pride? 2) does the lioness have to roll on her back and extend her back legs after mating to facilitate sperm entering the dorsally located tip of the uterine horn while the round ligament stabilises the terminal part of the uterine horn, and does this have a bearing on the fact that multiple copulations are required over a prolonged period for conception by lions? 3) do more ovulations take place from the bigger left ovary and? 4) are more conceptusses borne by the longer left uterine horn? The anatomical information obtained during this study was subsequently applied in a surgical study on sixteen lionesses using laparoscopy to perform laparoscopic ovariectomy and salpingectomy. The availability of these two laparoscopic procedures subsequently led to a wider interest to its application in population control of lions in the smaller national parks of South Africa.