Chronic wasting disease a threat to Arkansas deer?

State officials battling spread of neurodegenerative disease

Since late 2015, chronic wasting disease (CWD) has been found in Arkansas’ elk and whitetail deer. This is alarming because the infectious neurodegenerative disease, caused by misfolded proteins called prions, is fatal.

The Arkansas Game and Fish Commission has been working to contain the disease in northeast Arkansas counties. Armed with newly crunched numbers, in mid-April, Cory Gray spoke with Delta Farm Press about those efforts. Gray has been with the commission for 18 years mostly as a deer biologist and is currently research division manager. Among his comments:

On the history of CWD in the state…

“We began testing elk for CWD in 1997 and whitetails in 2003. We used a variety of strategies in that testing, especially with the whitetails.

“The first thing we did, to give us a baseline, was go into every county and collect 50 samples. We began to realize that not all samples were the same. With this disease, you have a higher probability of checking it in certain animals. For instance, you’re 11 times more likely to find CWD in roadkill. For sick, or ‘target’, animals you’re 16 times more likely to find it. So, we started placing more emphasis on those types of samples all the way up to 2016. 

“Our first positive elk was hunter-harvested in Pruitt, just north of Jasper. Since it’s such a limited hunt on our elk we always try to test them. The first hit was a cow harvested in October 2015 and got the test results back in February 2016.

“At the same time, a sick deer showed up at our elk education center in Ponca – right behind the building. A local biologist went down and pulled a sample, which was also positive. Both hits were in Newton County.”

Gut punch

When did you really get alarmed?

“The punch to the gut really happened that February. I was in a deer conference in North Carolina and I got a call from the lab in Wisconsin that does our testing. They said, ‘Cory, we’ve got a ‘suspect’ animal.’ That meant the elk tissue would be tested further for confirmation (of CWD).

“The good thing is we had a response plan in place and weren’t caught completely flat-footed. In 2006, we’d written the plan up, the commission approved it, and we put it on the shelf. So, in 2016 when the call came in, we took that plan down, dusted it off a little – some things had changed in 10 years, but not much – and began implementing it.”

How did it get into the state?

“We really don’t know and probably won’t ever find out. We’re the twenty-fourth state to find the disease and very few of those know where it originated. We don’t know if it was brought in, if it’s spontaneous.

“We are doing genetic testing and looking at the make-up of our elk and deer to give us some clues. We’re interesting in trying to identify the type of CWD we have and compare it to CWD in other states. That information will be very interesting.”

When will that information become available?

“Hopefully, within a year we’ll know. We’ve partnered with the University of Arkansas in Monticello and Fayetteville for both the elk and deer genetic projects.

“We’re checking the elk to see if it’s actually an Arkansas elk, did it escape from a high fence, or if it was imported. While we’re building the database, we’re extracting all the DNA and that can be looked at later for further research. We may want to isolate different alleles or characteristics.”

Spreading?

How far has it spread?

“The plan calls for us to determine prevalence. What’s the percentage of animals infected?

“The second thing it calls for is spatial distribution. How far-reaching is the disease?

“In March 2016, we randomly sampled 266 deer in the CWD area. We found a 23 percent prevalence in the focal area of Newton County. That’s a very high percentage.

“The best way to check how far out the disease had reached the best way is to check roadkill and target animals. We started that statewide and have continued it since last spring. We’re working with state police and highway departments to identify these animals and go out and pick them up. Those animals are valuable when you’re looking for the disease but they’re also cheap and easy to come by.

“Since January 2016, we’ve collected 2,478 hunter killed samples; 1,631 roadkill samples and 354 target samples. We have other types of samples we collect so we’re right at 5,000 total samples for 2016. We’re collecting again in 2017.

“Out of those 5,000 we found the disease in 206 whitetails and six elk. Those were found in seven counties, all in north Arkansas: Boone, Carroll, Madison, Marion, Newton, Pope, and Searcy.”

Is there any way you can you keep the disease isolated? Keep it above I-40?

“We’ve quit using the term eradicate. Once you’re over 20 percent prevalence, we’ll never eradicate it. So, we need to manage it.

“There are two main goals for managing CWD. One is to maintain the prevalence at, or below, 23 percent. We don’t want this to amplify.

“One way to do that is to increase bag limits. You don’t want a lot of deer on the landscape. They’re shedding the disease in their urine and saliva.

“The second goal is to maintain the disease in the CWD management area. We don’t want it to escape and go to another part of the state. The best way to do that is to keep everything within those counties. So, we have a carcass movement law that if you harvest a deer in one of the affected counties you cannot take the whole deer somewhere else. You can take our deboned meat, antlers and skulls but you can’t shoot a deer in Newton County and then drive it down to Bradley County.”

Threat potential

Potential threats to humans eating these animals?

“Right now, the World Health Organization and the Center for Disease Control say there’s no evidence can be transmitted to humans. They don’t say it can’t be but that, as of now, it doesn’t appear it does.

“I always tell hunters don’t eat a deer that appears sick. That’s regardless of whether it’s CWD or any other type of illness or injury. It isn’t wise to eat a sick animal – whether a deer or chicken. If the animal is acting oddly or you cut into it and find something that doesn’t look right.

“Secondly, we always encourage hunters to get their deer tested. There are Game and Fish check stations. We’re working with taxidermists throughout the state, with local vets that will accept deer. So, we’re trying to provide many avenues for hunters to get their animals tested.

“If it does turn up positive, call us so we can come and dispose of it.”

Can the CWD in elk and deer be transferred to livestock or other animals?

“There has been an extensive amount of work with this disease in cattle. CWD was found in Colorado and Western states where cattle production is huge. They’ve not been able to see this disease go into cattle.

“Now, ‘mad cow disease’ is similar to CWD. It’s in the same family as CWD but it has a different makeup.

“One of the things we’re interested in learning about is CWD in feral hogs. Arkansas is kind of unique in that we’re a Southern state with CWD, it’s in both deer and elk. But we also have a large feral hog population around the Buffalo River and wonder how those animals might be playing into this disease. Are they transmitting or amplifying it? Those are unknowns we want answers to.”

On outreach and education…

“We had several meetings on CWD last year and have already had one this year. Along with pamphlets and we’re utilizing social media more.

“Hunters may be getting phone calls – a random telephone survey -- asking their opinions regarding CWD. We’re working with the University of Arkansas Little Rock on that.

“Our hunters must be informed and be our partners in fighting this. If Game and Fish tried to manage this disease by ourselves we’d be fools and we’d fail.

“The biggest thing is we’re fortunate to not be the first to deal with this. We can learn from those who went before us.”

TAGS: Livestock
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