Abstract Background and Aims Felids are obligatory hyper-carnivorous mammals, representing the utmost manifestation of a carnivorous dietary adaptation. Chronic kidney disease (CKD) could be characterized as an epidemic amongst domestic and captive wild felids, affecting up to 87%. However, its aetiology remains yet unknown. The aim of the study was to assess how various diets influence the development of CKD in felids. Method Ninety adult, captive non-domestic felids (tigers, leopards, cheetahs, and lions) from zoological parks were examined under anaesthesia. Their examination and sampling were part of planned annual health evaluations, not related to experiments. Husbandry and dietary information, as well as medical history were collected through a questionnaire. Blood serum and urine were taken. For the staging of CKD, symmetric dimethylarginine (SDMA), the level of azotaemia (serum creatinine) and the level of proteinuria with the urinary protein creatinine ratio were evaluated and correlated to dietary, biological and management factors. Results Sixty percent of the felids were diagnosed with CKD. The risk for developing CKD was much higher in animals fed primarily with skeletal muscle meat only compared to animals being fed with meat containing bones or whole pray carcasses. Furthermore, the incorporation of fasting days was significantly linked to a lower CKD prevalence. In addition, feeding a combination of white and red meat showed a lesser association with CKD presence compared to exclusively feeding red meat. Conclusion Non-domestic felids in captivity are exposed to different feeding practices. Diets closer to natural, wild diets resulted in lower risks of developing CKD. Feeding strategies such as whole-body prey, the inclusion of white meat and the implementation of fasting days were associated to significantly lower risks of developing CKD in captive wild felids. Future studies on investigating the benefits of dietary supplements, the impact of the Calcium:Phosphorus ratio, the composition of meat and the structure of fasting days is needed. In addition, the role of chronic low-grade inflammation (inflammatory biomarker analysis) as well as the impact of various dietary regimes on the microbiota composition should be explored further.
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