EVALUATION OF MORTALITY CAUSES AND PREVALENCE OF RENAL LESIONS IN ZOO-HOUSED CHAMELEONS: 2011-2022.

Abstract

Of the 202 species of Chamaeleonidae, 38.6% are globally threatened. Currently, nearly a thousand individual chameleons from 36 different species are kept in zoological institutions worldwide. The objectives of this study were to assess the main mortality causes of chameleons in zoological institutions, the prevalence of renal lesions at necropsy, and the environmental factors associated with renal lesions. An online survey was sent to 245 zoological institutions worldwide to collect information about species and sex distribution, necropsy results, and husbandry parameters. Necropsy reports of the last 10 yr were requested from participating institutions (n = 65) when available. Mortality causes were classified into three categories (open diagnosis, infectious, and noninfectious), and noninfectious causes were further subdivided into seven categories (renal, reproductive, myoarthroskeletal, digestive, ophthalmologic, denutrition/multisystemic, and neoplastic). The prevalence of renal lesions was recorded. Multiple linear regression models were used with the prevalence of renal diseases as the dependent variable, and exhibit minimum and maximum hygrometry; exhibit highest and coolest temperature; as well as minimum, mean, and maximum hygrometry of the geographical area as independent variables, combining all chameleon species with similar environmental requirements. Results were obtained for 14 species (n = 412 individuals). The main mortality causes were infectious (46.8%), noninfectious renal (11.4%), and noninfectious reproductive (10.7%) diseases, with all cases of fatal reproductive diseases reported in females. Of the individuals that underwent renal histopathology, 41.7% displayed renal lesions. There was a tendency towards higher renal lesion prevalence in zoos located in areas with lower mean hygrometry (P = 0.05). Further research studies about infectious, renal, and reproductive diseases of Chamaeleonidae are warranted.