Official Newspaper of Eddy County since 1883

Controlling the Flames of CWD

A good number of movies about diseases – Outbreak, Contagion, Pandemic, even Dawn of the Dead -

have made it into the top ten on Netflix in recent weeks as fear and curiosity, along with free time have

spurred a desire to understand how diseases spread. And, like with Hollywood's tales, in real life,

outbreaks often start with just a spark of infection in a single patient. It is just as possible that the spark

smolders and dies out, taking with it only its host before it can be spread to any other member of the

species. Other times - as evidenced over the last 60 years with Chronic Wasting Disease (CWD), a

neurological disease caused by a prion (a sort of misfit, folded protein with incredible longevity) that

essentially eats holes in the brain tissue of cervids like deer and elk - the spark finds kindling in the form

of other hosts to infect, and begins to blaze a trail of destruction through the population.

With CWD now present throughout the upper Midwest and south central Canada, and several positive

tests in 2019 adding to the cases detected in North Dakota since 2009, the disease is at the forefront of

the North Dakota Game & Fish Department's (NDG&F) big game management issues. According to

NDG&F Wildlife Veterinarian Charlie Bahnson, D.V.M, that relative ease of transmission through saliva,

feces, urine and other bodily fluids of deer, and the ability of CWD to stay on the landscape through

those means, is fueling the flames of an epidemic that threatens the future of deer hunting across the

country.

"It was first recognized in a research facility in Colorado in the 1960s and then a number of years later

they started recognizing it in wild deer in the same area," Bahnson relates as to CWD's most likely

origins, "where exactly it originated is uncertain, but that's where we first saw deer infected with the

disease, it was this curiosity for a number of decades, but starting in the late 1990s and early 2000s, it

was seen in more and more states and more and more areas and was paired with a higher infection

rate," he added.

Once CWD is introduced into an area – through transport of live cervids, or the bodies of harvested

deer, moose, or elk – it remains present on the landscape and spreads. Those places with higher deer

densities have seen a greater prevalence of CWD in their herds, and a faster spread, to the point where

it is beginning to impact populations. The always-fatal disease, at its worst, could be picked up by a

fawn shortly after birth, limiting the deer's lifespan to an average of around 20 months. This in turn can

impact the number of mature deer on the landscape, ultimately decimating the number of older bucks

and does available for harvest, and create continuous population damage, both in terms of numbers and

quality, year-after-year, like a non-stop series of bad winters, according to Bahnson.

"We're early in that process, there's other parts of the country where prevalence will easily be 20 to 30

percent, and I've anecdotally even heard of populations where you're looking at 60 percent of hunter

harvested deer [being infected] within localized areas," Bahnson explains, "some of our eastern states

that are dealing with CWD are looking at deer densities of 40 to 50 to 60 deer per square mile, that's

just a lot of susceptible individuals in a small area, it's a recipe for rapid spread; in most of our area of

North Dakota, we're at four to six deer per square mile," he relates, suggesting that is one major factor

in helping slow the spread of the disease among the state's herds.

At this time, the CWD trends observed in other states with both whitetail and mule deer are playing out

across the northern prairie. In samples taken from hunter-harvested deer in North Dakota during the

2019 rifle season, nine mule deer bucks came back positive out of the 12 total animals with CWD.

Where the disease is established, it began predominantly with the male mule deer in the region and

then the does, before leveling out in the whitetail deer population shortly thereafter until it was fairly even across both species and their genders. While there may be physiological factors in play, Bahnson

hypothesizes that mule deer bucks, with larger territories and potentially more contact with other

animals, are more likely to get infected due to their heightened activity across the landscape. Currently,

it is estimated by the NDG&F from hunter-harvested samples taken in unit 3F2 last year in south central

North Dakota, that three percent of the mule deer population likely has CWD, and just under one

percent of whitetails in the area are infected. In northwestern North Dakota, positive samples from

dead deer on the landscape and taken from hunter-harvested animals have been found in units 3A1,

3B1, 4B and 4C. Where the disease goes from here is up to sportsmen.

"The ship has not sailed yet in North Dakota, we have a real opportunity where – yeah, we have it – but

collective action now means that we can keep this thing at bay in the long term," Bahnson states, "other

areas that have those alarmingly high infection rates, in all honesty, their options are pretty limited," he

continued, adding that sharpshooter teams, herd reduction tactics and other means of removal in those

eastern states are about all that can be used to lower the population densities and slow the spread of

CWD, with an extreme cost to agencies and taxpayers in terms of dollars, and to sportsmen in terms of

lost hunting opportunities.

Sportsmen serve as the firebreak against the flames of CWD and while now that it is established in the

region and will likely not die out, there are ways to prevent it from flaring up in the near term and

impacting the hunting opportunities of future generations. Hunters are encouraged to become familiar

with transport regulations designed to prevent the spread of CWD and to avoid using bait to attract deer

to hunting areas which would create a point where bodily fluids are easily transferred between animals.

Hunters should familiarize themselves with the NDG&F's Regulations on CWD and obey the laws in place

in those areas affected by the disease and the units adjacent to them which have baiting and other

restrictions set up to slow the spread of the disease. For more information, visit:

gf.nd.gov/wildlife/diseases/cwd.