State's wild deer might be in peril from chronic wasting disease

A deer killed by an archer in southeastern Minnesota last fall is believed to have been infected by chronic wasting disease, the first wild whitetail in the state to be stricken.

"This is very unfortunate," said Tom Landwehr, Department of Natural Resources commissioner. "Minnesotans have done much to prevent CWD from entering our wild deer population."

The DNR has been concerned about the spread of CWD to the state's wild deer since 2002, when the disease was first found in captive elk near Aitkin. Minnesota's wild deer number about 1 million, and because CWD is always fatal to deer and elk, the effect on the state's half a million deer hunters would be enormous.

CWD, which can be transmitted by animal-to-animal contact, is not believed to pose a danger to humans, though hunters and others who eat venison and elk meat are warned that an animal's brains and spinal cord should be avoided. The disease causes small lesions in brains of infected animals, degenerating their body condition and behavior.

Tests expected to be completed next week would confirm the infection.

Four elk in a captive herd about three miles from where the doe was killed were found to carry CWD in 2008, and the entire herd was killed by public health authorities.

"The DNR and other state agencies can't say definitively the deer was infected by a captive elk, but I believe reasonable people can make that connection," said Mark Johnson, executive director of the Minnesota Deer Hunters Association.

Surveys to begin

DNR and state public health officials were in the Pine Island area Friday morning, contacting landowners. Next week the DNR will begin aerial surveys over a region within about 10 miles of where the animal was killed to estimate the number of deer there.

Officials will establish the area as a CWD-infected zone and finalize a plan that will include killing and sampling a portion of deer there to see if the disease has spread.

It's possible the public will be asked to help kill deer in the area, DNR big-game coordinator Lou Cornicelli said. Or, DNR sharpshooters will be employed.

Given the difficulty of culling a large enough sample of deer to test, Cornicelli said, it's likely "as many deer as possible" will be killed for testing.

Very little of the animal has been eaten by the hunter or his family, the DNR said Friday, and authorities will pick up the butchered meat for further testing. The archer has asked to remain anonymous.

Long gestation for disease

Before it was shot, the animal appeared thin, the archer recalled, but otherwise it behaved normally. CWD can gestate in an infected animal for as long as four years before clinical signs of the disease are detected and the animal dies.

In addition to the infected herd near Aitkin, three other captive-elk herds, including the one near Pine Island, have been affected by CWD.

Landowners in the area will have the final determination on whether to allow hunting or sharpshooting on their property, said Ed Boggess, acting DNR fish and wildlife division director.

In deer and elk, CWD can be transmitted by animal contact, and can also be picked up from soil and the urine or feces of infected animals.

Ground where infected deer and elk have trod can remain contagious for years, officials say.

Cattle are kept inside the fences now at the Pine Island farm, but cattle are not known to be susceptible to CWD.

In Wisconsin, wildlife officials have not been able to eliminate CWD in wild deer, possibly because it was discovered after too many animals had been infected. But in New York, after one animal was found with CWD, further testing has discovered no other infected deer, Cornicelli said.