Endometrial glandular changes in aged captive cheetahs (Acinonyx jubatus) in southern Africa

Abstract

The cheetah, Acinonyx jubatus, is classified as “vulnerable” on the IUCN red list of threatened species. With declining population numbers in the wild, conservation efforts have focused on captive breeding and investigating the long-term effects of reproduction control strategies. Cheetahs in captivity survive longer than their wild counterparts and are purportedly more predisposed to conditions such as endometrial hyperplasia, cystic endometrial glandular changes, endometritis and pyometra. Uterine samples were collected from 21 captive aged cheetahs (mean and median age of 10 years) from three research conservation organisations in southern Africa. Endometrial changes from cheetahs sampled one year post-laparoscopic salpingectomy (n=7) were compared with samples collected at ovariectomy (n=7) or post mortem (n=7). Histological examination showed minimal endometrial pathology with only mild glandular ectasia (calculated as gland lumen area %) in most cases. This contrasts with previous studies in cheetahs, and other domestic and wild felids and canids where severe cystic and/or hyperplastic endometrial glandular changes were frequently reported. Increased age was positively correlated with increased gland lumen area (% and median) and endometrial area. There were no differences in endometrial changes between the post-salpingectomy and other samples. No notable endometrial changes were observed in the 10 cheetahs previously implanted with deslorelin as a contraceptive. It is possible that the observed mild endometrial changes are within the realm of physiological normality and not representative of overt pathology. This requires further investigation before new grading systems are developed to evaluate endometrial glandular pathology in cheetahs.