Region’s deer herd more likely to get CWD

PSU professor’s study shows Northeastern animals susceptible to the chronic disease

From Mirror staff reports

Northeastern deer are more susceptible to chronic wasting disease than those to the west, according to a Penn State professor’s research published this week in a peer-reviewed journal.

How to respond to the spread of chronic wasting disease in central Pennsylvania has been a wedge issue between numerous area hunters and the state Game Commission.

The Game Commission wanted to use sharpshooters to significantly reduce the deer population in southern Blair County to see if it would slow the spread of the disease.

The plan was shelved for at least a year after an outcry from hunters, who argue the commission should focus more on developing a vaccine for CWD.

State and federal lawmakers are weighing in on the dispute.

How genetics might affect the debate remains to be seen.

A release Friday from Penn State revealed after testing more the 2,200 deer, David Walter, professor of wildlife ecology at Penn State, identified the genetic markers that reliably predict which animals are most vulnerable to CWD.

The 11 markers his team of researchers selected are easy to interpret and are likely to provide a common platform to benefit future genetic studies, such as those for CWD, a press release states.

Additional studies nearly complete by Penn State researchers outline a genetic method to determine when a CWD-positive deer is discovered, where it came from and whether it is a wild or captive-bred animal.

According to the university, that information will guide wildlife managers’ reaction as they decide whether to establish disease-management areas and targeted removals of deer to slow the spread of CWD.

The study published in BMC Genetics found deer in the Mid-Atlantic region to be more genetically susceptible to CWD.

“The genetic variants that would make deer less susceptible to chronic wasting disease are in much lower frequency in the East, likely because they weren’t needed,” read a statement attributed to Walter. “Over a long period of time, their survivability may have been somehow favored by losing these genotypes. They weren’t important until a disease like chronic wasting disease showed up. We have seen that deer with the more susceptible genotypes are in the majority.”

Over the last decade or so, Walter’s research group in Penn State’s College of Agricultural Sciences has been studying how the movement, behavior and genetics of wild deer are affecting the spread of CWD. The disease belongs to a group of similar diseases such as mad cow disease and scrapie in sheep, called transmissible spongiform encephalopathies.

Walter noted that the disease was first seen in mule deer in Colorado in 1967 and has been spreading eastward across the continent since. It now infects deer and elk in 24 states and several Canadian provinces, and has been found in reindeer, moose and red deer in three Scandinavian countries.

“In the U.S., CWD spreads differently in the East than in the West, because deer numbers and densities are so much higher in the East,” said Walter, who is also assistant unit leader of Penn State’s Pennsylvania Cooperative Fish and Wildlife Research Unit. “We have been trying to unravel the genetic nuances to understand where chronic wasting disease is likely to show up.”

In earlier published studies, Walter and colleagues determined that geographical features such as rivers, mountain ranges and high ridges have channeled CWD spread in the East. Even manmade features such as highways appear to have influenced deer movement, guiding where CWD in deer has been discovered.

The Pennsylvania Game Commission, the Maryland Department of Natural Resources and the Virginia Department of Game and Inland Fisheries supported Walter’s research.