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View Full Version : CWD illness hit 50% of captive herd




Tom Morang
03-30-2002, 04:37 PM
Wasting illness hit 50% of herd

Tests show CWD is highly virulent in white-tailed deer

By Todd Hartman, News Staff Writer, Rocky Mountain News

March 30, 2002

About half of the white-tailed deer within an 800-acre enclosure in northwestern Nebraska have tested positive for chronic wasting disease, a staggering total that surpasses by far any known infection rate for the deadly disease.

Though test results from the herd have trickled in for months, the new numbers -- 79 positives out of 154 deer -- are nearly final, pending a handful of additional lab results. They show a voracious spread of the disease unmatched outside of research pens in Fort Collins.

"Obviously, it's a great reason for concern," said Todd Nordeen, a Nebraska Game and Parks Commission biologist. "From the start, it's kind of surprised everybody (the rate) was that high."

The numbers buttress emerging belief among scientists that CWD is more contagious among white-tailed deer as opposed to mule deer and elk, in which infection rates in the wild typically hover around 5 percent and 1 percent respectively.

It's especially alarming in Nebraska and points east, where white-tailed deer herds are far denser than in Colorado.

The latest infection figures for the captive deer herd come after Nebraska officials killed off the last of animals two weeks ago to prevent the disease's spread. CWD was first discovered within the herd in November of 2000. Since then, no live deer or elk have been permitted to enter or leave the facility.

Particularly alarmed by the new Nebraska figures are Wisconsin officials, who are scrambling to assess the distribution of CWD. Initially three wild white-tailed deer tested positive, and two more were announced Friday.

That state, home to an estimated 1.6 million white tails, fears the disease may spread like fire in a dry forest.

"We realize we're up against a problem of significant magnitude, and we're not taking it lightly," said Sarah Shapiro Hurley, a deputy administrator for Wisconsin's Department of Natural Resources.

Already, that state is on a mission to kill and test 500 deer in a 415-square-mile area surrounding the place where the three infected deer were found. They hope to find the disease contained to a small focal area, but fear it may be more widespread.

Bruce Morrison, overseeing the CWD control effort for Nebraska's wildlife commission, said that while the infection rate inside the pen is very high, it has festered there for nearly 18 months -- plenty of time for it to spread in a relatively confined space.

"Our bigger concern is what could be outside the pen, in the wild population," he said.

So far, it appears the disease hasn't moved as aggressively in the rugged pinelands surrounding the captive herd. In a state-run hunt in late January, Nebraska biologists shot 113 wild deer within a 5-mile radius of the enclosure. Nine of those animals tested positive.

Even better news arrived more recently, when Nebraska and South Dakota workers teamed up to kill 183 animals along the border between the states, and north of the enclosed herd. None of those animals were found with CWD.