How many elk have been affected by CWD in North America?
Chronic wasting disease primarily affects wild deer and elk, appears to be rare and spreads very slowly. The USDA reports that, of the more than 5,000 wild deer and elk that have been tested since 1990, only 110 clinically affected animals had been identified with CWD. Generally, less than 1% of the wild elk and 5% of wild mule deer in the affected areas are believed to be CWD-positive. The incidences of CWD in farm elk and deer are even more rare. Those that have been identified are being eradicated. A total of 13 herds in the United States had at least one animal diagnosed with CWD: two in Colorado, one in Montana, two in Nebraska, one in Oklahoma and seven in South Dakota. Of those, seven herds (one in Colorado, one in Montana and five in South Dakota) have been depopulated. Canada has eight herds with at least one case of CWD, including the source herd, which has likely been infected for 10 years. So far, only 16 of the elk in the eight Canadian herds have actually tested positive
