Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/6/2016
Publication Date: N/A
Technical Abstract: Background: Interspecies transmission studies are an opportunity to better understand the potential host ranges of prion diseases. Chronic wasting disease (CWD) of cervids and scrapie of sheep and goats have a similar tissue distribution of abnormal prion protein (PrPSc) and prion disease exposure across species could occur in pasture or range situations. We previously demonstrated that white-tailed deer are readily susceptible to scrapie from sheep after intracranial or oronasal inoculation, but less is known about the potential for sheep to develop CWD. Objective: To determine the susceptibility of sheep to CWD from white-tailed deer after intracranial inoculation. Methods: Suffolk lambs (n=15) were inoculated intracranially with brain homogenate from CWD-infected white-tailed deer. After inoculation, sheep were observed daily for the occurrence of clinical signs. Immunohistochemistry (IHC), enzyme linked immunosorbent assay (ELISA), and western blot were performed on brain and lymphoid tissues to assess for PrPSc accumulation. Results: Two sheep developed clinical signs and were euthanized and necropsied at 26 and 36 months post-inoculation. PrPSc was demonstrated by ELISA and IHC in the brainstems of these sheep and one additional sheep that did not develop clinical signs. The majority of sheep were negative by IHC, ELISA and western blot of brain. PrPSc was not present in lymphoid tissues of any animal in this study. Conclusions: CWD from white-tailed deer is transmissible to sheep, but with a limited attack rate and detection of abnormal prion protein in the brain only.