The state has received test results on all but 28 of the 1,940 deer tissue samples collected in late 2002 as part of a effort to monitor the disease, Kanta said. Most were donated by hunters.

Chronic wasting disease, or CWD, attacks the brains of infected deer and elk just as mad cow disease, or bovine spongiform encephalopathy, affects the brains of cattle. Both diseases are fatal. However, unlike mad cow, CWD has never been shown to spread to cattle or humans.

Nonetheless, medical experts have recommended against eating venison or other parts of deer or elk that appear sick.

CWD was first observed in mule deer in Colorado in the late 1960s. It has since spread to wild or captive deer and elk herds in 11 U.S. states and in parts of Canada.

Mad cow disease, which has never been found in the United States, was detected in Britain in the mid-1980s. A related human ailment has killed some 130 Europeans who presumably ate beef from infected cattle.

Five of the diseased South Dakota deer were killed last fall by hunters who voluntarily submitted the animals' heads for CWD testing. Two were killed by state employees after exhibiting signs of illness, and one was struck by a vehicle in Rapid City.

CWD was first confirmed in South Dakota in 1996 in a captive elk herd, and the disease was later found in four other captive herds. Animals in all five herds were destroyed, Kanta said.