With the archery deer season across Michigan off to a good start and the firearm season opener still a month away, the Department of Natural Resources continues to be vigilant in monitoring the state's herd for every deer and elk manager's biggest nightmare -- chronic wasting disease (CWD).

An always fatal neurological disorder -- similar to mad cow disease -- that is caused by a mutated protein, CWD reared its ugly head in Michigan in August of last year when it was discovered in a captive whitetail in a privately owned facility in Kent County. The facility was immediately depopulated and closed, but DNR officials were concerned about where the disease originated.

Records at the facility indicated the deer had been born in the pen and no deer from states known to have CWD in their deer populations had been imported into the facility. And none of the deer that were removed from the facility tested positive for the disease. One of the DNR's concerns, however, was that a pocket of CWD might exist in the free-ranging deer population in the immediate area and that's how the captive deer was infected.

So the DNR initiated a widespread testing program looking for CWD. Every deer from the township with the infected deer -- and all of the adjoining townships, as well -- were required to be tested. In addition, the DNR sampled deer statewide for the disease.

All that testing failed to produce another CWD-positive animal.

"Last year, we tested 1,523 deer from the nine-township area and we looked at a total of 9,341 across the state," explained Steve Schmitt, the DNR veterinarian. "We didn't find anything.

"But we're still looking, both in captive facilities and free-ranging deer to see if we'll find a small pocket of the disease," Schmitt continued. "We know we don't have a big outbreak of it like they do in Wisconsin or Illinois or Colorado. But we can't yet say for sure that we don't have a small pocket of it."

Mandatory testing in the nine-township area will continue this year. Hunters are required to bring any deer harvested from the area to a DNR check station where they can either completely bone-out the deer and take home the meat -- as they are required to do if they kill a deer or elk in a state known to have CWD in its herds -- or they can leave the carcass in a refrigerated truck until the test results come back.

CWD testing involves collecting the head of the animal and examining the lymph nodes. The testing is carried out at the Diagnostic Center for Population and Animal Health at Michigan State University where Schmitt and his crew have a state-of-art laboratory.

This year, the DNR will cut back on the number of animals it tests outside the nine-township area, focusing on targeted animals -- either those that are showing symptoms of the disease (such as emaciation, drooling, a loss of equilibrium, and no fear of humans) or animals that died from unknown causes. The deer that were tested from the epizootic hemorrhagic disease (EHD) outbreak this past summer and fall in southeast Michigan, for instance, also were tested for CWD. And the DNR will test another 300 animals from Kent County outside the nine-township area this fall, too.

Schmitt said he'll recommend that mandatory testing in the nine-township area continue through at least next year.

"Each year that goes by that we don't find it we become more certain that it didn't spill over into the wild," he said. "If we test 4,500 animals in the nine-township area over a three-year period and don't find it, we'll have a better handle on it, but there's still chance we could have it out there."

The DNR began testing for CWD as it began spreading in other states in 1998 and has tested some 32,000 free-ranging deer, 1,100 elk and 50 moose. Meanwhile, the Department of Agriculture has tested some 10,000 captive cervids (mostly whitetails) without finding the disease -- until last summer.

Other safeguards that have been put into place, including a Lower Peninsula-wide deer baiting and feeding ban that went into effect immediately, will remain in place for the foreseeable future, too.

"If the disease does get into the state, either from an infected carcass from out of state that was handled improperly or from an infected live animal, we know the bait and feeding ban will help keep the disease from becoming established in the deer population," Schmitt said. "It could help keep CWD from spreading rapidly."

One mystery remains, however: Where did the disease that infected the Kent County animal come from?

"We'll never know for sure how it got in there," Schmitt said. "The most important thing for us was to figure out if it was in the free-ranging population. It could have been in the free-ranging population and spilled into the captive facility. We were concerned about that and also the other way -- that it was in the facility and spilled into the free-ranging population.

"Now it appears more likely that it didn't come in from the free-ranging population, but we'll never know."

But Michigan wildlife managers are sighing in relief that what looked like an ominous day for the future of Michigan's deer and elk herds -- the day CWD was discovered in Michigan -- so far has not left permanent marks on the state's deer and elk populations.

More information about CWD is available on the state of Michigan's Emerging Diseases Web site at www.michigan.gov/chronicwastingdisease.