ARS | Publication request: EXPERIMENTAL TRANSMISSION OF CHRONIC WASTING DISEASE (CWD) TO CATTLE

Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 19, 2000
Publication Date: N/A

Technical Abstract: To determine the clinical signs, nature of lesions, and comparison to natural bovine spongiform encephalopathy (BSE) and experimental scrapie in cattle, calves were inoculated intracerebrally with brain suspension from mule deer naturally affected with CWD. Between 24 and 27 months post inoculation, 3 animals became recumbent and were euthanized. Gross necropsies revealed emaciation in 2 animals and presence of a large chroni pulmonary abscess in the third one. Brains were examined for protease- resistant prion protein (PrPres) by immunohistochemistry and Western blotting, and for scrapie associated fibrils (SAF) by negative stain electronmicroscopy. Microscopic lesions in the brain were subtle in 2 animals and absent in the third case. However, all 3 animals were positive for PrPres by immunohistochemistry and Western blot, and SAF were detected in 2 of the animals. A non-inoculated control animal euthanized during the esame time-period did not have PrPres in its brain. These are preliminary observations from a currently in-progress experiment. Three years after the CWD challenge, the 10 remaining inoculated cattle are alive and apparently healthy. These preliminary findings demonstrate that diagnostic techniques currently used for BSE surveillance would also detect CWD in cattle should it occur naturally.