Schwabenlander, M.D., G. Rowden, S. Stone, R. Shoemaker, L.L. Lindsey, J.D. Oliver, L. Glaser, M. Carstensen, J.C. Bartz, W.D. Walter, R.J. Larsen, T.M. Wolf, P.A. Larsen. 2022. Implementing a veterinary forensics approach to investigate chronic wasting disease at a deer carcass disposal site. Wildlife Disease Association Meeting, Madison, WI, 23-29 July 2022.
Abstract
Chronic wasting disease (CWD) is confirmed in 29 US states, three Canadian provinces, and in Sweden, Norway, Finland, and South Korea. Although its geographic origin is speculative, much of the disease spread in North America over the past seven decades is attributed to human activities that include the movement of live animals and animal carcasses. Given the potential for CWD-causing prions to remain infectious within the environment, the disposal of CWD-positive animal remains, whether from free-ranging or captive sources, can play an important role in the transmission of CWD. Regulatory agencies provide guidance and proper disposal opportunities for the control of CWD in endemic areas and to reduce the risk of introduction to new areas. Upon the discovery of an illegal carcass dumping site associated with a CWD-positive captive cervid facility, we employed a veterinary forensics approach to investigate the existence of CWD-positive materials within the site. Animal remains were examined to determine species, age, sex, relatedness, and CWD status. We utilized advanced anatomic, entomologic, genetic, and prion amplification methods to discover CWD-positive remains across multiple age classes of white-tailed deer. CWD prions were detected via RT-QuIC in 13 of 49 carcass samples with 9 of 13 from fawns, 1 of 13 from a yearling, 2 of 13 from adults, and 1 of 13 from a deer of unknown age. We also identified CWD-positive fly larvae associated with positive remains. Our multi-methods approach provides the foundation for the veterinary forensic investigation of CWD spread by means of cervid carcasses.