USDA Seizes Vermont ‘Mad Cow’ Sheep. One of two flocks in which sheep had tested positive for TSE (transmissible spongiform encephalopathy), the generic term for the class of “prion diseases” that includes sheep scrapie, BSE, and new variant Creutzfeldt-Jakob Disease in humans, was seized in a commando-style raid, the shepherd says before he could mount a challenge to what he says was an improper testing process. These diseases are probably just species-specific names for one process; the prions can be passed across species by consuming infected tissue, and cause an inevitably fatal neurodegeneration after a scarily long incubation period responsible for the former name for the conditions, “slow virus diseases”. What this may mean is that there are multitudes of cases currently incubating; perhaps a die-off of epidemic proportions is in store for us.