Ultrasonographic and laparoscopic evaluation of the reproductive tract of the captive female African lion (Panthera leo)

The use of transabdominal ultrasonography to assess the oestrous cycle has not been previously described in the African lion (Panthera leo). Twelve sexually mature lionesses and five female cubs had their reproductive organs assessed by transabdominal ultrasound. Ovarian findings were compared to laparoscopic findings while performing laparoscopic ovariectomy or salpingectomy. Vaginal cytology was performed and serum progesterone levels were determined. By combining all data the oestrous cycle stage of each lion was determined. One lion was far pregnant and was not operated on. In adults a uterine body could be seen ultrasonographically in 67% of lions while mural structures could be distinguished in 44% of lions. Five uterine horns could be seen in 3 lions. In 12 adults 10 ovaries were found of which eight had discernable follicles or luteal structures. During laparoscopy 12 active ovaries were seen with luteal structures seen in 11 ovaries and follicles in 2 ovaries. Using laparoscopy as the gold standard, ultrasonography had a sensitivity of 66% and specificity of 83% to detect ovarian reproductive activity. Two uterine cysts and a cluster of periovarian cysts were seen in three different lions. Three lions were pregnant, two were in oestrus, three in a luteal phase (dioestrus), and four were in anoestrus. Transabdominal ultrasound in combination with serum progesterone levels and vaginal cytology can be used to assess ovarian cyclical activity with reasonable accuracy in captive bred lions.