Degenerative Joint Disease in Captive Large Cats: the radiographic characteristics and clinical presentation of DJD in captive cheetahs (Acinonyx jubatus), lions (Panthera leo) and tigers (Panthera tigris)

Abstract

Lions, tigers and cheetahs are commonly held in zoos, experiencing greater longevity in captivity than the wild. As a result, they are more likely to develop age-related diseases, including degenerative joint disease (DJD). However, the prevalence, distribution, severity and clinical presentation of DJD in these species is currently unclear. To address these knowledge gaps, 14 institutions provided radiographic studies and matched clinical records for all cheetahs, lions and tigers that underwent imaging between 1979-2019. Radiographic arthropathies were identified and the correlation between arthropathy status and a range of predictors was examined. Radiographic DJD status was then matched with clinical entries to investigate the presenting signs of DJD in these three species. Arthropathies were found to be common and almost exclusively degenerative in nature. Increasing age was the strongest predictor for joint disease, and a significantly lower prevalence of disease was recorded for the cheetah. Whilst all species showed unique patterns of disease, similarities existed between the lion and tiger, with severe axial DJD a feature. There was a conspicuous absence of appendicular DJD detected in older cheetahs, however axial DJD is reported in this species for the first time, with both increased prevalence and severity found in cheetahs from urban compared with open-range zoos. The meniscal ossicle and supinator sesamoid bone were identified as normal structures that become radiographically evident with skeletal maturation, with the supinator sesamoid bone reported in the tiger, and the meniscal ossicle in the Sumatran tiger, for the first time. A spectrum of DJD-associated presenting clinical signs was established for the three species. Combined, these findings will facilitate radiographic diagnosis of DJD and enhance understanding of the clinical impact of this disease in captive nondomestic felids, whilst also providing impetus for further research in this area.