Experiment in Mission Texas:
The clinical signs of Downer Cow Syndrome were presented by cattle inoculated intracerebrally in 1979 with Scrapie-agents in Mission, Texas. When slaughtered 43, 44, or 73 days later their brain did not (yet?; a.) show the histological findings of Spongiform Encephalopathy. But inoculated into mice it produced central nervous system signs in them. And tissue from the cattle were found to be positive for prion protein [8], indicative of Spongiform Encephalopathy.