No CWD is found in wild deer samples
Harrisburg — The worst fears about chronic wasting disease in Pennsylvania have not been realized, Walt Cottrell told game commissioners here recently.
At least, not yet.
Speaking at the board’s Jan. 27-29 quarterly meeting, the agency’s wildlife veterinarian revealed that CWD was not detected in samples from deer killed this fall in the disease management zone.
That 400-square-mile area was established around an Adams County deer farm where CWD was discovered in two captive deer last fall. As a result, the Game Commission conducted tests on brain tissue from 2,051 deer killed by hunters, shot by farmers for crop damage or hit by vehicles.
“It’s a good outcome for us,” Cottrell said of the negative tests. “This gives us every reason to believe that this index case was confined behind that fence.”
But the state’s wild deer population is not out of the woods yet, related to CWD, Cottrell suggested. And the search for CWD in the commonwealth has by no means ended.
Because the always-fatal-to deer-and-elk disease is slow to develop – taking as much as five years to show up after infection – some of the tested-negative animals could still have been sick. That means CWD could by discovered in coming years.
“CWD has a very slow incubation period and a deer sampled could have had it and not been detected,” Cottrell explained.
But he noted that he is as worried about CWD “walking into the state” as being transported in a game-farm truck.
Chronic wasting disease has been found in wild deer in West Virginia, Virginia and most recently in Maryland, about 10 miles from the border with the Keystone State. It’s likely, the disease will spread into Pennsylvania from there, Cottrell noted, carried by a wild deer.
“It seems to be headed in our direction,” he said. “The terrain in that area seems to favor that.”
The commission has a CWD biologist assigned to monitoring for the disease along the border in Bedford, Fulton, Franklin and Somerset counties.
The Game Commission continued its statewide CWD surveillance again last fall by collecting tissue samples from thousands of hunter-killed deer around the state.
Brain tissue samples were also taken for testing from all of the elk taken by hunters last November. Results of all those tests are pending.
Cottrell pointed out that the commission will collect extra samples from within its disease management area for at least four more years. Road-killed and other deer along the Pennsylvania-Maryland border will also be collected and sampled.
Threat from deer-urine lures
Commissioner Ron Weaner, – whose district includes the disease management area in Adams and York counties – asked Cottrell for his opinion on the CWD threat posed by scent lures, made from deer urine collected on deer farms.
They are used by many bowhunters to attract bucks into shooting range.
Those lures have probably spread the disease, Cottrell replied, adding that there is no question among scientists that deer urine is a conduit for spreading the prions that cause the disease is.
“That is not a matter that is in doubt,” he said.
“I don’t feel compelled to quantify that probability. I feel compelled to mitigate that possibility,” he said, clarifying why he favors banning the use of deer urine lures.
At least one commissioner seemed skeptical, however.
Commissioner Brian Hoover, of Delaware County, countered that there’s no proof that urine products have spread CWD. To ban them would have enormous economic consequences, he contended.
“We can’t say or prove that has extended the disease,” he said. “Before we jump to conclusions, I’d like to see some more information on that.”
Cottrell disagreed. “To me, the urine-based scent lures are like a basket of corn,” he said. “They serve as both an attraction to concentrate deer and a potential contact point for spreading anything among the animals, including the prions that infected deer disperse in their urine.”
Commissioner Jay Delaney pointed out that some other states have instituted complete bans on urine-based scent products. “We may be importing deer urine into Pennsylvania that we’re spreading around our soils,” he said. “Do you want to be proactive or reactive.
Commissioner David Putnam, of Centre County, asked Cottrell whether urine-based products have not been implicated in any CWD cases.
“No, but nobody knows how it came east of the Mississippi River,” he said.