A Deer-Slayer Crosses the Mississippi
By Janet Ginsburg
Nancy and Charlie Fochs did everything right. When they bought 160 hilltop acres near the Wisconsin Dells to start an elk ranch seven years ago, they were careful to select only purebred stock. They tested their herd for tuberculosis. They put up a $70,000, seven-foot-high fence. And since 1998, they have been one of only a handful of the 800-odd deer and elk producers in the state to test for chronic wasting disease (CWD)--a plague similar to mad cow disease that affects deer and elk.
But for all their efforts, a cloud of uncertainty now hangs over their dream. Test results announced at the end of February confirmed the first cases of CWD in the state--the first east of the Mississippi--in three white-tailed bucks killed by hunters last fall in Dane County, not far from the state capital, Madison. Now, wildlife officials are planning to kill and sample 500 deer in the area to find out whether the disease has spread. Whitetail may be more susceptible to CWD than elk, sparking fears that there could be hundreds of infected deer in a two-county area. That would rank it among the worst outbreaks ever--and raises the specter that the disease may have spread throughout the East.
At the Nanchas Ranch--named after Nancy and Charlie--the 80 elk munching hay on a sunny March afternoon appear to be perfectly healthy. But an animal with the always-fatal CWD can take well over a year to show symptoms. Researchers aren't sure exactly how the disease spreads--or even at what stage it becomes infectious. There is no vaccine. And the test, which requires a brain sample, can only be done after an animal has died.
Now, the Fochses and the rest of the state's producers face a ban on animal shipments--though not on their feed and vet bills. "I'm scared we're just going to sit here with animals. What are we going to do with them?" asks Charlie, a former electrician, sitting in the living room of his new home overlooking vistas of rolling pastureland.
The Fochses are part of an alternative livestock revolution that began in the U.S. during the 1970s and blossomed in the '90s. From ostriches to llamas, niche agriculture was sold as a way for small producers to stay on the land. "We can't compete growing corn or beans or cattle," says Steve Wolcott, owner of Elk & Bison Co. in Paonia, Colo., and a past president of the North American Elk Breeders Assn. But shipping restrictions have destroyed the lucrative markets for breeding stock and "trophy" bucks that are sold to private hunting ranches. CWD fears have also caused South Korea, the largest importer of antler velvet, which is used in Eastern medicine, to shut down trade.
Wisconsin is gearing up for war, requesting millions of dollars from the Agriculture Dept. (USDA) to help fight the disease. The state is worried about much more than a budding livestock industry with an estimated 20,000 animals. Deer hunting in Wisconsin generates $32 million in license fees and delivers a $1.3 billion economic punch. What if hunters, fearful of CWD, stop hunting? And with a $20 billion dairy business, there's concern about whether the disease could jump to cows. So far, ongoing studies indicate that there is no risk to cows either from contact with sick deer or from eating CWD-contaminated feed. But cows that have been injected with CWD into their brains have gotten sick. State representative and Crawford County cattleman DuWayne Johnsrud says that some producers in other states have expressed concern about buying Wisconsin animals. "The collateral damage due to the perception that we have it is real," he says.
Economics is only part of the equation. "We are absolutely dependent on hunters to help us manage our deer population," says Julie Langenberg, a wildlife veterinarian with the state's Natural Resources Dept. Wisconsin has 1.5 million deer, which is about 500,000 too many, she says: "Whole ecosystems are in trouble--both agricultural and forest lands." Although hunters take 460,000 deer each year, Langenberg's department still has to shell out $1.5 million annually for crop damage.
The population explosion has led to another pricey problem: deer dashing into cars. There are 50,000 such collisions in Wisconsin each year. Take away hunting, and that number could easily triple, says Langenberg. Nationally, the figure is estimated in the hundreds of thousands, says the National Safety Council, causing dozens of human deaths, countless injuries, and insurance claims approaching $1 billion.
CWD, like mad cow, is a transmissible spongiform encephalopathy (TSE)--also known as a prion disease. A prion is a normal protein molecule that folds a particular way in healthy animals. But "rogue" prions fold differently. They act like seed crystals, creating a pattern that other prions mimic. Over a period of months, years, or decades, these misshapen prions lead to brain lesions and death.
Can CWD infect humans? There has only been one study. Scientists at Rocky Mountain Laboratories in Hamilton, Mont., found that CWD prions were able to convert human prions at a very low rate--about the same rate that mad cow converts human prions. Later this year, the first major CWD study involving nonhuman primates is scheduled to begin at the National Prion Disease Pathology Surveillance Center in Cleveland.
CWD has never been linked to a case of Creuzfeldt-Jakob disease (CJD), the human TSE. Recently, a team led by Dr. Ermias Belay at the Centers for Disease Control & Prevention in Atlanta investigated three cases involving venison-eating victims under age 30. CWD was ruled out, though no cause was determined. Belay points out that in 85% of CJD cases the cause is never found. Further complicating the picture, only 40% of suspected CJD cases in the U.S. are autopsied--which is the only sure way to make a diagnosis.
But the fear alone of CWD could have far-reaching effects. There are close to 12 million deer and elk hunters in the U.S., says the Fish & Wildlife Service. Although there are no records of how many animals they kill, 8 million to 10 million is a conservative estimate. There are also no records on how much hunter-killed venison is consumed, since it isn't USDA-inspected. "Venison is social meat here. It's the stuff used for football game chili and put into sausages that are given as Christmas gifts. It's a prize shared with family and friends," explains Wisconsinite Kathy Lee, whose husband John is an avid bow hunter. "Everybody's scared," she says, and many hunters are clearing their freezers.
While contaminated livestock feed is the agent of infection in mad cow disease, researchers suspect that CWD spreads through physical contact such as "nose kissing," or browsing in forage contaminated by infected urine and feces. There is evidence that prions--which can withstand freezing as well as temperatures of 1,000F--can survive in the ground. "I think there are analogies between TSEs and the AIDS virus," notes John Stauber, co-author of Mad Cow USA and a Madison resident. "People weren't able to grasp the immensity of a type of infection that broke so many rules. This is a great example of a situation that can be prevented if it's caught in time."
It has been more than 30 years since the first cases of emaciated, slobbering mule deer were observed in a wildlife testing facility pen in Colorado. In the wild, about 1% of elk and 5% of mule deer are thought to have CWD in an 8,500-square-mile area of Colorado and Wyoming.
Farmed elk may have picked up the disease from their wild cousins--fence-jumping and through-the-fence nose-kissing are common. But elk farming has played a key role. A contact disease is more dangerous when animals are kept at close quarters. And given such a long, symptom-free incubation period, elk that looked healthy but were in fact sick were shipped all over the U.S. and Canada. Now, states such as Texas--which has a multibillion-dollar game farm industry--are banning imports. It could be too late. "It became clear to me that it didn't matter that we were 900 miles away from the endemic area," says Langenberg, explaining why Wisconsin became one of the first states to test wild deer three years ago.
The fight to contain CWD has already been costly. Last year, Canada spent millions to slaughter more than 7,000 elk from several suspect farms. In January, an elk on yet another farm tested positive. CWD has also popped up in recent months on farms or in the wild in South Dakota, Kansas, Nebraska, and Colorado--where 1,500 farmed elk were incinerated. The USDA has released funds to reimburse producers as much as $3,000 per head. An additional 4,500 wild elk and deer near Fort Collins, Co., will be culled shortly.
Meanwhile, Langenberg points to a map on a computer screen. There have been at least 20 escapes from whitetail farms across Wisconsin over the past two years. And unlike Bessie the cow, when Bambi makes a break for it, he can easily fade into forest, perhaps carrying a deadly disease. No one may ever know how CWD got into Wisconsin. Langenberg just hopes they'll be able to stamp it out.
Ginsburg, based in Chicago, writes about science and the environment.
Edited by Harry Maurer