In August 2002 Louisiana’s deer hunters woke up to headlines they had hoped never to see: Wildlife officials had begun testing deer for chronic wasting disease — an always-fatal brain infection that could wipe out a state’s deer herd and close hunting seasons.
Two years after those alarms, wildlife managers and hunters are breathing a sigh of relief — but only a small one. While tests on thousands of wild and captive deer have turned up no trace of the disease, they know the threat will be a permanent part of their lives.
“We’re two years into a five-year intensive sampling program, and so far so good — no sign of CWD,” said Dave Moreland, administrator of the Wildlife Division at the state Department of Wildlife and Fisheries. “But even if we get no positives after five years, that won’t mean we’re out of danger.
“Once detected in a wild population, this disease has never been eradicated, and it seems to be spreading. About the most you can hope to do is contain it when it shows up.”
Similar to mad cow disease, CWD afflicts only deer and elk. It was first recorded on deer farms in Colorado in the early 1960s, according to the Chronic Wasting Disease Alliance, a coalition of conservation groups. By the early 1980s it had spread to wild and pen-raised elk or deer in nine states and two Canadian provinces.
The most damaging outbreak has been in Wisconsin, where in two years the state has killed more than 20,000 deer in five counties in an effort to stop the disease from spreading. Nonetheless, it was later found next door in Minnesota.
The Midwest infections sent alarms rippling across the Southeast because southern hunters and game farms are prime customers for pen-raised deer from that region. Landowners and hunting clubs in the South long have attempted to improve the size of local deer by introducing the larger-growing animals from the Midwest into their herds.
State wildlife agencies, concerned about CWD, have attempted to control deer farming and import operations. But most states, including Louisiana, have decided to treat the operations as part of a fledging farming industry and given control to departments of agriculture.
Louisiana, like most Southern states, had placed a temporary ban on importation of deer in response to the CWD outbreaks. Under terms of the ban, the only deer that can be allowed into the state are those raised at farms and in states that had been certified by that state to be CWD-free. In states who have no history of CWD, that would take three years of testing; in states with a CWD incident, approval would require five years of testing with no positive results.
But in the summer of 2002 a shipment of deer came into Louisiana from Minnesota, a state with a record of CWD. It was later revealed the conditions of the state’s ban allowed the Commissioner of Agriculture to provide personal exemptions, which accounted for the Minnesota shipment.
When news that 22 deer from an infected state had entered Louisiana, DWF and sporting groups became alarmed. The resulting controversy resulted in an intense search for the deer. Since the only method of testing for the disease is to take a sample of brain tissue, the animal must be killed. Eventually all were found, and none tested positive for CWD.
That scare also set the state upon the first stage of what officials now say will be a permanent CWD monitoring program. It calls for DWF biologists to test more than 1,000 wild deer in each of the next five years, and the DAF to test deer from all of the state’s approximately 200 commercial deer farms.
Thus far, the DWF has tested more than 2,000 hunter-killed deer and the DAF has tested 345 captive deer with no positive results, according to officials from both agencies. Intensive testing will continue for another three years, since wildlife researchers believe the disease has an incubation period that can last five years. Researchers think the most likely form of transmission is through contact with fecal matter. Deer farm operations are considered the most likely centers of transmission. Wildlife officials said their greatest fear is that an infected pen-raised deer might escape and contaminate the wild population.
“Our plan is to test 1,000 wild deer a year for five years, with most of the sampling coming from areas around where these deer farm operations are located,” Moreland said. If there is a positive result, the DWF would then move into intensive culling of deer in the immediate area the positive test came from.
“Your typical whitetail spends its life in about a one-square mile area, so we would concentrate our search in that area first, then slowly expand outward, if we had to,” Moreland said. But Louisiana would not try to duplicate Wisconsin’s massive effort to quickly eradicate all deer in a large area.
“We’d utilize hunters by increasing limits and extending the seasons,” Moreland said. “We’d be looking to see if any more deer in this area had been exposed.”
If no positives are reported after the initial five-year period, testing would be reduced, but would continue indefinitely.
“We’ll probably continue to check for this forever, doing random sampling of hunter-killed deer, and also testing any dead deer that are found,” Moreland said. “We’ll concentrate around the deer pens, because that’s where the outbreaks usually have started.”
Maxwell Lee, the state veterinarian at the DAF, said monitoring of pen-raised deer would also continue indefinitely.
“We’ve requested all of our licensees to notify us immediately and submit any deer that die at their operations – regardless of the reason. If a captive deer dies, we would want to know right away. ”
Lee said he expects the deer-importing business to resume in the next few years as deer operations in other states complete the monitoring programs.
“It requires three years of negative tests for operations that are in states that have never had a positive, and five years for outfits in states that have had CWD deaths,” Lee said. “Right now I’m not sure there’s an operation in the country that qualifies, so that isn’t an issue.
“But as they reach those requirements, then we’ll see more deer coming into the state. And we’ll monitor all those operations.”
Moreland said if an outbreak occurs in Louisiana, it probably won’t come as a surprise, or from a wild deer. The history of the disease to date revolves around outbreaks at deer farms, and in wild populations adjacent to those operations.
“I think most wildlife people see this as something that — if it happens — will probably be obvious and easy to trace,” he said. “We’ll probably just see a slow progression down the states in the Mississippi valley.
“Hopefully that won’t happen. Hopefully these monitoring programs will prevent that. That’s why we’ll be monitoring for this for the indefinite future.”