Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2010
Publication Date: 10/30/2010
Citation: Greenlee, J.J., Smith, J.D., Kunkle, R.A. 2010. White-tailed deer susceptible to scrapie by natural route of infection [abstract]. American College of Veterinary Pathologists. Paper No. 81.
Technical Abstract: Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. Previous experiments demonstrated that white-tailed deer are susceptible to sheep-derived scrapie by intracranial inoculation. The purpose of an ongoing study is to determine susceptibility of white-tailed deer to scrapie after a natural route of exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal (1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep clinically affected with scrapie. Non-inoculated deer were maintained as negative controls. All deer are observed daily for clinical signs. Deer are euthanized and necropsied when neurologic disease is evident. One animal was euthanized 15 months post-inoculation (MPI) due to an injury. At that time, examination of brain and lymphoid tissues by immunohistochemistry (IHC) and western blot (WB) were negative. A second deer developed pneumonia and was necropsied at 28 MPI. Tissues from this deer were positive for scrapie by IHC and WB. Tissues with PrPd immunoreactivity included brainstem and various lymphoid tissues including tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. The remaining deer are under observation for clinical signs. This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by potential natural routes of inoculation. In-depth analysis of tissues will be done to determine similarities between scrapie in deer after intracranial and oral/intranasal inoculation and chronic wasting disease resulting from similar routes of inoculation.