Abstract:
The study uniquely described the clinical value of transabdominal ultrasonography for
monitoring features characterizing the estrous cycle in female cheetahs (Acinonyx jubatus). The
reproductive tracts of 21 female, nulliparous, and relatively aged (median: 11 and interquartile
range: 9.25–14 years) captive cheetahs resident on two sites in Namibia were assessed by
transabdominal ultrasound. Subsequently, the ovarian findings on ultrasound were compared
with direct visualization while performing laparoscopic sterilization. A combination of these
observations supported by concurrent sampling for vaginal cytology and serum progesterone
concentrations defined the estrous status of individual animals. At one site, six cheetahs had
been implanted with the GnRH agonist, deslorelin as a contraceptive at least once within the
preceding 11 years. On ultrasound, 31 uterine horns and 35 ovaries with discernible structures
on 28 (86%) were visualized in the 21 cheetahs. The uterine body was difficult to visualize
because of its intrapelvic location. Eleven of 19 uteri (58%) visualized showed endometrial
edema suggestive of estrogenization. The uteri of four cheetahs (19%) showed evidence of mild
cystic endometrial hyperplasia. Paraovarian cysts were seen on ultrasound (n ¼ 21) and laparoscopy
(n ¼ 26) in 16 (76.2%) and 18 (85.7%) cheetahs, respectively. Ovarian volumes obtained
from ultrasonographically determined dimensions predicted cyclic activity.
Laparoscopy showed that 19 ovaries had discernible follicular structures. In the study population,
10 (47.6%) cheetahswere in proestrus or estrus; none in the luteal phase; and 11 (52.4%)
in anestrus. Transabdominal ultrasound, in combination with serum progesterone concentrations
and vaginal cytology, was used with acceptable accuracy to assess cyclic ovarian activity
in captive cheetahs. A considerable proportion of this aged population showed ovarian
activity and the prevalence of paraovarian cysts was notable. A history of prior deslorelin
treatment was not associated with either reproductive activity or uterine pathology.
