State finds 1st probable case of CWD in wild deer

Published 2:39 pm Friday, January 21, 2011

MINNEAPOLIS — Minnesota wildlife officials have found the state’s first probable case of chronic wasting disease in a wild deer, which was shot near the southeastern town of Pine Island, the Department of Natural Resources announced Friday.

It was one of 524 deer tested during the fall hunting season in the Pine Island area, northwest of Rochester, the DNR said. The agency expects to get confirmation from the National Veterinary Services Laboratory in Ames, Iowa, next week but is already moving ahead with a response plan developed several years ago.

Officials said there’s no evidence that CWD can spread to humans, nor is it known to affect livestock such as cattle. But the disease is fatal to deer, elk and moose, and experts recommend against eating meat from an infected animal.

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Lou Cornicelli, the DNR’s big game coordinator, said they hope it’s an isolated case and that a fast response can stop it from spreading through the state’s deer herd.

Still, DNR Commissioner Tom Landwehr said the discovery has “serious implications.” He noted that Minnesota has nearly half a million deer hunters, and that deer hunting has a large impact on the state’s economy.

Researchers don’t know exactly how CWD is spread, though they think it passes from animal to animal through feces, urine or saliva, and that deer can catch it from contaminated soil. It’s caused by abnormal proteins called prions, not bacteria or viruses.

The disease causes brain degeneration and is always fatal. Symptoms can include a drooping head or ears, poor physical condition, tremors and stumbling. The hunter told DNR officials his deer seemed thin but that it behaved normally.

Cornicelli said the DNR will soon conduct aerial surveys to determine the deer population in the Pine Island area, designate a CWD management zone, get more samples from other deer in the area and ban the feeding of wild deer in the zone.

Officials said they need more data before they decide whether to reduce the deer population in the area. To get the samples, the DNR may conduct a special public hunt this winter, issue permits to landowners or use sharpshooters. One complication is that nearly all the land in the area is privately owned, and the DNR has no authority to go on private land without the owner’s permission.

There are 12 deer or elk farms within a 10-mile radius of where the affected deer was shot, said Paul Anderson, assistant director of the Board of Animal Health. The board will temporarily stop the movement of deer and elk off those farms until the owners can convince the board they’ve put up adequate fencing to keep their herds separated from wild deer.

The infected doe was shot by an archer in late November about 3 miles from where the disease was detected in a captive elk herd near Pine Island in 2008, but Cornicelli said there’s no way to tell if there’s any connection. That herd was destroyed, and the high fences around the property remain up under an agreement between the landowners and the DNR.

Anderson said a few deer have gotten into that enclosure, probably when a gate was accidentally left open, but to his knowledge all were killed. He said test results were pending on three deer shot inside the fence in the last week or two.

There’s also a small cattle herd on the property that’s not considered at risk, Anderson said.

CWD was first detected in Minnesota in 2002 on an elk farm near Aitkin, but tests on more than 32,000 hunter-harvested deer, moose and elk across the state since then have turned up no probable cases in the wild until now.

The disease has been present in a large part of Wisconsin for many years, but the DNR found no cases in 500 samples taken along the Minnesota-Wisconsin border in 2008 or in 2,685 samples in southeastern Minnesota in 2009. Wisconsin’s CWD management zone is about 50 miles from the Minnesota border, but the closest confirmed case there was shot about 150 miles from the probable case here, Cornicelli said.

The hunter who took the deer prefers to remain anonymous, said Ed Boggess, acting director of the DNR’s Fish and Wildlife Division, who also said very little of the meat has been eaten.