Retrospective study of captive jaguar Panthera onca mortality in the European breeding population from 1998 to 2018

The jaguar Panthera onca is classified as Near Threatened by the IUCN, and the population in the wild is decreasing. To date, no studies on the causes of mortality in jaguars in European zoos have been completed. Therefore, this study was conducted to determine the most common causes of mortality in captive jaguars in the European breeding population between 1998 and 2018. A total of 206 jaguars died during the study period. Causes of death were obtained for 53.8% of the population. Most deaths (51.4%) occurred in geriatric animals, while cubs accounted for 22.3% of deaths. Trauma was the leading known cause of death for the study population (21.6%), affecting primarily cubs and characterised by lethal wounds inflicted by the dam or sire. Cub survival was unaffected by dam parity (P=0.21, OR=0.8, CI=0.46-1.2) or litter size (P=0.09, OR=0.6, CI=0.42-1.28). It is likely that factors such as underlying disease, zoo management and husbandry could influence cub survival. Neoplasia is an important cause of death for the study population (19.8%) and evidence of metastasis was found in over half of those cases. Mammary and liver carcinoma were the most common tumours. This study identifies recent trends in mortality in the European breeding population of jaguars, which can be used to guide preventive medicine programmes. Inconsistencies in record-keeping suggest that a unified necropsy protocol for jaguars in European zoos is needed to gather standardised information and improve understanding of jaguar mortality.