Yearly Archives: 2003

Illinois Deer Season Update: Firearm Season Sampling Finds Additional CWD Cases in Northern Illinois

SPRINGFIELD, ILL. — Nine additional cases of chronic wasting disease (CWD) have been detected in northern Illinois – including one in DeKalb County – as a result of testing conducted on samples collected from hunter-harvested deer during the first firearm season this fall, Department of Natural Resources Director Joel Brunsvold announced today.

The new cases bring to 30 the total number of confirmed cases of the disease found in the state since November 2002 when the first positive was discovered.

“An intensive surveillance effort has been underway this season and last,” Director Brunsvold said. “Hunter cooperation has been terrific and has allowed us to effectively track CWD in Illinois. In addition, I want to commend the staff members at the Department of Agriculture who are conducted the testing. Their professionalism has been a great asset during this effort.”

One of the nine new cases of CWD was detected in a deer harvested by a hunter near Kirkland in northwest DeKalb County. The other recent cases of CWD were found in deer taken by hunters in Boone and Winnebago counties.

Of the 30 cases of CWD confirmed in Illinois to date, six were from eastern Winnebago County, 21 from Boone County, two from McHenry County, and the other is the recent DeKalb County case. Before the 2003 hunting season, the distribution of the disease appeared to be confined to an area northeast of Rockford and one in McHenry County, but the recent finds indicate that isolated cases are turning up over a slightly wider area.

“The current distribution of chronic wasting disease in Illinois consists primarily of a core area northeast of Rockford in which the disease is most common, with scattered cases occurring infrequently at distances up to about 20 miles around it,” said IDNR Forest Wildlife Program manager Paul Shelton. “In addition, we had the two cases near Woodstock in McHenry County in 2002, but have yet to find any others so far this year.”

Shelton said that it is unknown whether these new findings are the result of recent movements of infected deer, or if the disease has been present in those outlying locations for some time at very low levels which are difficult to identify through surveillance.

The IDNR this fall collected tissue samples from more than 4,000 deer taken by hunters in 36 counties during the seven-day firearm season. A few hundred samples also were collected from deer harvested by archery hunters in northern Illinois in October and November. All samples collected are submitted for testing at Illinois Department of Agriculture labs in Centralia and Galesburg. Samples taken from northern Illinois counties during the second season, and from most southern Illinois counties during the first season, have yet to be completed.

Based on preliminary figures, deer hunters in Illinois harvested a record total of nearly 104,000 deer during the seven-day firearm hunting season Nov. 21-23 and Dec. 4-7. Archery hunting continues statewide through Jan. 15.

“We want to again thank hunters in Illinois for their support of our CWD surveillance effort, which is working well in identifying areas where chronic wasting disease is present,” said Shelton. “Knowing where the disease is and how many cases we have is essential in developing our strategy for battling CWD in the Illinois deer herd.”

While testing of samples collected this fall continues, IDNR biologists this winter will be involved in additional CWD management and surveillance. In parts of those counties from which CWD has been identified, trained IDNR and USDA sharpshooters will be used to collect additional samples and to reduce the size of localized deer populations known to be infected. This approach is used to remove potentially sick animals from the landscape and hinder the spread or establishment of the disease, while providing significant disease information on a more local scale.

While not contagious to humans or livestock, CWD is known to spread from animal to animal among deer and elk. The disease affects the brains of infected animals, causing them to become emaciated, display abnormal behavior, lose coordination and eventually die.

Director Brunsvold noted the DNR has taken a number of steps to reduce the deer population throughout Illinois and provide additional hunting opportunity to sportsmen. Thousands of additional permits were made available around the state, for both the regular firearm season and the muzzleloader season. Hunters also were allowed to use handguns during the firearm season, a change welcomed by Illinois sportsmen.

In addition, Governor Rod Blagojevich this year signed legislation (HB2918) giving the Deparment of Natural Resources another tool to combat CWD or other diseases found in the deer herd. The new law allows DNR to set up special harvest periods, if deemed necessary, to reduce the deer population as part of a disease-control strategy. In keeping with IDNR’s adaptive approach to CWD management, biologists will examine all information gathered this fall and winter before determining whether to implement any special seasons or making recommendations about possible changes for next year.

Illinois expanded its chronic wasting disease surveillance effort in 2002 following the discovery of CWD in neighboring Wisconsin. For updated information about chronic wasting disease, check the IDNR web site at: A web application that allows participating hunters to check the status of test results for deer sampled during the firearm deer season is available at that site.

USDA Makes Preliminary Diagnosis of BSE

WASHINGTON–Agriculture Secretary Ann M. Veneman today announced that the U.S. Department of Agriculture has diagnosed a presumptive positive case of bovine spongiform encephalopathy (BSE) in an adult Holstein cow in the state of Washington.

“Despite this finding, we remain confident in the safety of our beef supply,” Veneman said. “The risk to human health from BSE is extremely low.”

Because the animal was non-ambulatory (downer) at slaughter, samples were taken Dec. 9 as part of USDA’s targeted BSE surveillance system. The samples were sent to USDA’s National Veterinary Services Laboratory in Ames, Iowa. Positive results were obtained by both histology (a visual examination of brain tissue via microscope) and immunohistochemistry (the gold standard for BSE testing that detects prions through a staining technique). Test results were returned on Dec. 22 and retested on Dec 23.

USDA has initiated a comprehensive epidemiological investigation working with state, public health, and industry counterparts to determine the source of the disease. USDA will also work with the Food and Drug Administration as they conduct animal feed investigations, the primary pathway for the spread of BSE.

This investigation has begun while the sample is being sent to the world reference laboratory in England for final confirmation. USDA will take the actions in accordance with its BSE response plan, which was developed with considerable input from federal, state and industry stakeholders.

BSE is a progressive neurological disease among cattle that is always fatal. It belongs to a family of diseases known as transmissible spongiform encephalopathies. Also included in that family of illnesses is the human disease, variant Creutzfeldt-Jakob Disease (vCJD), which is believed to be caused by eating neural tissue, such as brain and spinal cord, from BSE-affected cattle. USDA has determined that the cow comes from a farm in Washington State and as part of the USDA response plan, the farm has been quarantined. After the animal was slaughtered, the meat was sent for processing and USDA’s Food Safety and Inspection Service is working to determine the final disposition of products from the animal.

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Officials Fighting CWD Ponder a Natural Partner: Wolves

The spread of chronic wasting disease toward Yellowstone’s famed game herds alarms wildlife lovers, but two top researchers think biologists will discover a powerful ally in an old frontier villain.

The wolf.

Wildlife managers have never controlled a major outbreak of chronic wasting disease, a fatal neurologic malady of deer and elk first discovered in a captive Colorado mule deer herd in 1967.

No one knows for sure if wolves would target CWD-infected deer and elk, but wolves’ uncanny ability to spot vulnerable animals may make them the best natural control for the disease, researchers say.

Even in its early stages, CWD makes its victims distracted and unwary as it eats tiny holes in their brains. That’s a fatal liability in the presence of a running predator like the wolf, National Park Service biologist Douglas Smith said.

“Wolves show up and say, ‘Let’s see what you’ve got,”‘ said Smith, who helped lead the program that returned wolves to Yellowstone in 1995 and 1996. “And if you don’t have it, they laser in on you like a fighter pilot. The things they pick up on are incredibly subtle.”

While the theory is still unproven, Colorado’s top wildlife manager says it is worth factoring in to the blistering debate over how to manage wolves that may soon migrate into the state.

“Every idea should get a fair hearing and I think disease management is a fair question for a biologist to ask,” said Russell George, director of the Colorado Division of Wildlife.

Some scientists are skeptical of wolves’ ability to contain CWD. David Mech, a biologist with the United States Geologic Survey who is considered the world’s top wolf expert, cautioned that until wolves and wasting disease actually interact, such theories are just speculation.

“But that is a reasonable possibility,” he said.

The speculation isn’t simply academic.

CWD was first identified in a Fort Collins wildlife research station in 1967. By the 1980s, it spread across a 30,000-square-mile area of northeastern Colorado and neighboring Wyoming. In the late 1990s it appeared in Nebraska and South Dakota. But the real shock was in 2002, when CWD was discovered in Wisconsin and on Colorado’s Western Slope.

Many consider CWD the biggest single threat to wildlife in North America.

No one has been able to study whether wolves single out CWD-infected animals because the range of predator and disease have never overlapped.

But over the next few years, that will likely change.

This summer, an infected mule deer was discovered in Bighorn Basin north of Cody, Wyo., on Yellowstone’s doorstep.

Some Wyoming biologists fear CWD will move into the Greater Yellowstone ecosystem in the next year or two.

But Mike Miller, a CWD expert and research veterinarian for the Colorado Division of Wildlife, thinks northwestern Wyoming’s robust wolf population will eliminate infected deer that try to move into the park.

“No one knows for sure,” Miller said. “But I think wolves could help the disease from becoming established to begin with. Sick animals just won’t survive that long.”

The earlier infected animals are killed, the less opportunity they have to transmit the disease.

Colorado has plenty of CWD but no wolves, although it’s just a matter of time before they migrate here from Yellowstone, experts say.

Predation by mountain lions and coyotes appears not to have slowed the spread of the disease in Colorado and Wyoming. But wolves are a different kind of hunter, Smith and Miller said.

Mountain lions are ambush specialists: They attack any deer or elk that they can surprise. Coyotes are too small to hunt adult deer, although they kill fawns and can severely injure adults.

By contrast, wolves constantly test potential prey, including elk, deer, moose and bison, looking for weakness. Sometimes wolves kill healthy adults, Smith said, but most of the time they find some vulnerability in their victim.

It could be a calf or fawn separated from its mother, a bull or buck worn out from the rut, a doe caught in deep snow, a cow elk with arthritis.

This hunting style, Smith said, seems perfectly tailored to removing sick animals.

“Wolves are probably the single best way to stop the spread of CWD,” he said. “Chronic wasting disease causes animals to act weird. Wolves kill animals like that.”

University of Calgary professor Valerius Geist, an expert on deer and elk, is also convinced.

“Wolves will certainly bring the disease to a halt,” he said. “They will remove infected individuals and clean up carcasses that could transmit the disease.”

Scientists still don’t know if CWD is a naturally occurring brain disease or if it jumped to deer and elk from sheep, which get a similar brain disease called scrapie. In the 1980s, scrapie jumped to British cows that were being fed sheep bits as a source of protein. The result was a huge outbreak of mad cow disease, which killed 100 Europeans who ate infected beef.

Deer and elk naturally gnaw on bones to obtain needed minerals. Researchers suspect the animals may contract CWD by eating brains or spinal tissue of dead animals, or grazing near their carcasses.

Geist and Princeton University biologist Andrew Dobson theorize that killing off the wolf allowed CWD to take hold in the first place.

A federal predator control program in the 1920s eliminated the last prairie wolves in the region, according to Michael Robinson of the Center for Biological Diversity.

While CWD was first identified in 1967, its prevalence in Colorado and Wyoming suggests it appeared several decades before that.

“Remove the wolves and 20 to 50 years later you have a problem,” Dobson said.

Federal wildlife officials are considering whether to reintroduce the wolf to Colorado’s San Juan mountains. Rocky Mountain National Park is also evaluating wolf reintroduction to deal with an overpopulation of elk.

And experts expect the animal will naturally make its way down from Yellowstone.

Colorado officials are drafting a wolf management plan, outlining if and where it would be appropriate to have wolves in the state.

Two polls in the past 10 years show two-thirds of Coloradans would like to see the wolf returned to the state.

But stockmen, who fear wolf attacks on their herds, and hunting groups worried that wolves will take game meant for hunters, vociferously oppose the notion.

“We don’t think CWD will annihilate a herd, but there are several instances of herds that we think were annihilated because of the wolf,” Wyoming outfitter Maury Jones said. “Wolves will be far more devastating to a herd than CWD.”

Wolf researchers say those claims are false, but at the Division of Wildlife, George wonders whether Coloradans could tolerate enough wolf packs to reduce clusters of CWD infection on the Western Slope, where the overall infection rate is about 1 percent of animals.

“How often would a wolf be in proximity to an animal in a stage of the infection that made it vulnerable?” he asked.

It’s a different situation in Yellowstone, which is considered fully occupied by the 17 wolf packs living there.

Veterinarians have managed to control small CWD outbreaks on captive game ranches, but only by slaughtering every animal in the exposed herds – at a cost of more than $12 million in Colorado alone. Wisconsin is trying to eliminate all 25,000 white-tailed deer in a 1,150- square-mile area near the state capital, Madison, in a desperate attempt to eliminate an outbreak discovered in 2002.

In a limited trial, Colorado biologists are testing the tonsils of every deer in a herd and killing the infected animals.

Wolves would essentially do the same culling work for free, the theory goes, although they would likely also kill livestock and pet dogs.

Researchers may well have a chance to study how effective wolves can be in stopping the disease. Waves of wolves radiating out from Yellowstone are approaching the northern borders of Colorado and Utah. And in Wisconsin, wolf packs are within 70 miles of the CWD zone.

But retired Wyoming Game and Fish veterinarian Tom Thorne thinks animosity against wolves will be tough to overcome.

“Emotions against wolves are so strong that I’m not sure this potential benefit, which I agree might be there, would sway the opinions of many folks,” he said. “I think it would be a long, long time before people are used to wolves enough to admit they might be doing a bit of good.”

9 New CWD Cases Found in Northern Illinois

Illinois has nine more confirmed cases of a fatal deer disease first discovered in the state last fall near Roscoe, wildlife officials announced Friday.

The new cases were found among 1,100 hunter-harvested deer tested for chronic wasting disease during the first session of the firearm season last month.

The latest cases include five in Boone County, three in Winnebago County and the first-ever in DeKalb County. The state now has 30 confirmed cases.

Paul Shelton, state Department of Natural Resources wildlife program manager, said the DeKalb deer was killed in the county’s northern section near the Kishwaukee River about 20 miles from Roscoe, where the majority of the cases have been found.

“It’s possible it could have traveled from the Roscoe area,” he said. “Or it’s possible we could have missed a pocket (of diseased deer) during our sampling where we don’t have as high a prevalence of CWD among the deer. When more data comes in, we’ll get a clearer picture.”

The tests also showed CWD in two other new areas — just west of Rockton and northeastern Boone County. The Rockton case was the first west of Interstate 90, while the earlier Boone cases were all on the western border along Winnebago County.

“The numbers in themselves were not surprising. They were in line with what we expected,” Shelton said. “More important than the numbers is the distribution of the (positive) samples.”

The latest results were from tests in Winnebago, Boone, DeKalb, Stephenson, McHenry and Ogle counties.

About 3,500 samples were taken during the firearms seasons in northern Illinois, but not all the tests have been completed.

Shelton contacted hunters with deer testing positive Wednesday night.

He added the DNR appreciates the cooperation hunters have provided during the testing process. “They’ve been fantastic.”

Roscoe hunter Jim Hart said CWD has gained a level of acceptance among the majority of his colleagues.

“A certain number of hunters have told me they are terrified of (CWD), but most are accepting of it,” he said, adding he knows of some hunters who quit the sport this year for fear of the disease.

2003 CWD Hunter Surveillance Efforts Completed

LARAMIE — Statewide surveillance to monitor chronic wasting disease (CWD) is finished, thanks to new testing procedures that allowed the Game and Fish Department to analyze more than twice the number of samples in half the time.

The ELISA (Enzyme-Linked Immuno Sorbent Assay) test, which certified in 2002, allowed G&F researchers, to analyze samples from 6,171 deer and elk before the new year. That compares to 2,550 samples analyzed by mid-March last year.

“In the past, we used to rely on the immunohistochemistry or IHC testing procedure, which was very time consuming,” says Hank Edwards, G&F disease specialist. “Whereas the new ELISA testing procedure has a much faster turnaround time, allowing us to analyze tissue samples in six weeks rather than six months. We have also switched from collecting the brain stem to collecting the retropharyngeal lymph nodes. Research has shown that early stages of CWD can be detected in these lymph nodes before it can be detected in the brain stem.”

Last spring, the G&F decided to conduct statewide surveillance during the 2003 big game hunting seasons to try to learn more about the distribution of the disease. That strategy was not impossible without the new test procedures and new equipment purchased through a federal grant.

“We learned a lot about the distribution of CWD in Wyoming during this expanded effort,” Edwards said. “In spite of the doubled workload only 156 animals tested positive, compared to the 115 positives last year, but we were able to document CWD in seven new hunt areas.”

The new hunt areas include 13 (Lusk), 41 (Worland), 70 (Shirley Basin), 74 (northwest of Laramie), 79 (Snowy Range), 81 (Sierra Madres) and 164 (Worland).

Hunter participation was key to the G&F’s efforts to monitor the prevalence and distribution of CWD. Testing was voluntary, but many hunters were more than willing to participate in the effort, in spite of the inconvenience. The G&F posted test results on their Web site and notified hunters by letter if their animal tested positive.

The World Health Organization says there is currently no evidence that CWD in deer and elk is transmitted to humans, but they further state no part or product of any animal with evidence of CWD or other transmissible spongiform encephalopathies, the name for that group of diseases, should be fed to any species – human, domestic or captive animal.

Although there is no evidence CWD is transmitted to humans, G&F is charged with managing the wildlife in the state, and officials want to continue to monitor the disease and its effects on wildlife.

Targeted surveillance also plays a role in monitoring CWD. Earlier this year targeted surveillance, taking animals that exhibit signs of CWD, revealed CWD in three new deer hunt areas 6, 8 and 80. The Department will continue with targeted surveillance efforts throughout the upcoming year.