So far there is no evidence that BSE can be transmitted from resistant animals, such as chickens or hamsters, to more susceptible species, but Race and Chesebro said more research is needed.
Hamsters suffer from their own prion disease, called scrapie, to which mice are completely immune.
Race and Chesebro injected the infectious agent for hamster scrapie into the brains of mice. Although the mice did not develop signs of the disease, the scientists found that a year after the mice were infected, their contaminated brain and spleen tissue could cause the disease when it was re-injected into hamsters. The scientists voiced particular concern about poultry raised for human consumption, and said feed containing animal carcasses should not be fed to any animals. Britain banned such feed for cattle in 1988, but it was still fed to pigs and chickens until it was outlawed for all animals in 1995. Britain also slaughtered millions of cattle to eliminate the epidemic and reduce the risk of any possible transmission to humans.