A Survey of the Reproductive Lesions in Captive Female Non-Human Primates in Italy

Non-human primates (NHPs) are considered important models for the study of reproductive diseases, due to their anatomical and physiological similarities to humans. However, studies on spontaneous lesions of the reproductive system in NHPs housed in zoos remain limited compared to those in laboratory animals. In this study, we report a retrospective analysis of female reproductive pathologies in 103 necropsied non-human primates from Italian zoos between 2007 and 2024. Only adult, intact, non-pregnant females with macroscopically visible reproductive lesions were included. Histopathological examination revealed reproductive tract lesions in 15 individuals (14.6%), including both non-neoplastic (cystic endometrial hyperplasia, adenomyosis, endometriosis) and neoplastic (leiomyomas, cervical and ovarian adenocarcinomas, and metastatic tumors) conditions. Leiomyoma was the most common tumor, particularly in the genus Macaca, while rare malignant neoplasms and metastatic lesions were identified in the great apes and in the New World species. The results suggest an age-related degenerative component and highlight interspecific differences in the distribution of lesions, probably related to the reproductive physiology of the various species. These results underline the importance of systematic post-mortem surveillance to improve the management of reproductive health of these captive populations and provide comparative insights with humans.