But regulations vary by state. Wisconsin game farms, for instance, can import any animal as long as it possesses an interstate health certificate, according to state veterinarian Clarence Siroky. These imported elk caused Wisconsin's Department of Natural Resources to test the brains of 250 wild deer last year, and all came back negative. Other states apparently think there's a risk, too. Alberta and Saskatchewan are also looking for it.
Game farms are prime test sites.
Though they're fenced, game farms provide many opportunities for contact between captive and wild animals. Gates are left open. Even when captive animals don't escape, such openings allow wild deer to come in, mix, and leave. After CWD was detected at a South Dakota game farm in 1998, for example, one of the 30 free-ranging whitetails harvested outside the fence tested positive. Steve Wolcott, past president of the North American Elk Breeders Association, thinks this focus on game farms ignores a key avenue for spreading CWD around the country.