Abstract

Amyloidosis is a chronic, protein misfolding disease that causes pathology through the accumulation of misfolded amyloid A protein in visceral organs, often leading to death of the animal. The continued increase of amyloidosis in captive cheetahs (Acinonyx jubatus) is of grave concern for the species, yet nothing is definitively known about its mechanism of transmission. One hypothesis is that amyloidosis is transmissible, similar to prion diseases. Transmission models from other prion diseases, such as scrapie and chronic wasting disease, were used in conjunction with cheetah demographic and disease data collected from the cheetah species survival plan (SSP) pathologist and cheetah stud book, in order to determine the likelihood that amyloidosis is infectious based on past captive transfers and historical amyloidosis infections. The likelihood of infection transmitting between cheetahs housed together was quantified using odds ratios. Odds ratio for mid-level exposure was 0.603 (p=0.362; CI: 0.199–1.787) and for low-level exposure was 0.695 (p=0.555; CI: 0.203–2.320), so there was no significant effect of exposure to infected cheetahs on development of amyloidosis. To refine the comparison, metapopulation models were designed, populated with demographic and transfer data, and compared with infection data. While our analysis does not disprove the infectious transmission route, transmission is not supported based on our initial findings. This study utilized a subset of the captive population, and, given that the results contradict previous reports, a broader population survey should be pursued.

Acknowledgments

The authors thank Dr. Karen Terio for her expertise and assistance in providing cheetah demographic and disease data. Thank you to Jessica Serbin for her assistance in developing the model and code. Thank you to Kailin Huang and Rachel Chmelovski for their assistance in data collection.