What I learned about CWD after 17 years of direct involvement

[Sytes]

Informative reading, around the table. Hopefully it remains civil long enough to continue a quality thread.

 

[Stay Sharp]

The unit I hunted deer in this year had a mandatory check for CWD if you were successful. Someone had pointed out that at the check station that the same tools used for taking samples, were used on every animal.
Will this give a false/positive test?

I will assume they were taking lymph nodes as the sample material. While its possible, I doubt exterior cross contamination would result in a false positive. But that said, no CWD test is 100% definitive. Part of the city and town culling I do on deer requires I summit all heads for testing. In 2 1/2 weeks I get a report back. This is the disclaimer that accompanies every report I get.


"Thank you for participating in the Chronic Wasting Disease deer sampling effort.

CWD was not detected in deer # 386699.

Tissue from the deer you provided the Wisconsin DNR for chronic wasting disease (CWD) testing has been examined for CWD prions. There were no CWD prions found and therefore no evidence that the deer was infected with CWD. However, the inability to find CWD prions in the tissue examined is NOT equivalent to pronouncing this deer absolutely free of CWD prions or stating that it is safe to consume. All laboratory tests for CWD only assess the presence or absence of a detectable amount of prions in the specific tissue examined at the time the tissue was collected. A recently infected animal may not test positive because prions have not yet reached a detectable level in the tissue that was tested. CWD testing is clearly of value for disease surveillance to learn where the disease exists, but it has limited value in the context of food safety testing. If you have additional questions about CWD, check the DNR website: dnr.wi.gov, keyword "CWD".

 

[squirrel]

some state agencies (like Wisconsin) made that mistake and then retracted. We are now in a test/monitor/track mode.

https://www.researchgate.net/publication/228624931_Predicting_Deer_Hunter_Harvest_Behavior_in_Wisconsin's_Chronic_Wasting_Disease_Eradication_Zone

A TEST??? "HEY CAN WE CHARGE $ FOR THAT Joe?" Joe says YEP...

Monitor? not so simple set up a meeting for next week... We'll put our best minds on it

Tracking? "you know Joe's nephew got fired down at the feed mill he could run it."

Sarcasm aside I disagree with your lab coat solution, I think it is a darwinian solution at the end making the drastic reduction in herd numbers even more the opposite of what is needed.

 

[BrentD]

Informative reading, around the table. Hopefully it remains civil long enough to continue a quality thread.

It would help, immensely, if citations to real research publications were provided. A lot of this is completely new to me. Thus, I'm pretty skeptical of many, many of the claims here.

 

[BuzzH]

Yes, there are different strains due to very small differences in the deer vs elk gene that codes for the protein, but there is still a lot to figure out. To the best of my knowledge, the strains appear transmissible cross-species, but may result in differences in incubation periods, amplify differently in the body, and prolong or shorten disease course. Those new transgenic mouse models are enabling them to really start getting at some of these differences.

https://www.pnas.org/content/116/25/12478

So with that thought in mind, assuming that cwd strains cross between deer and elk...how would managing cwd be at all practical to focus on mule deer while ignoring and doing nothing to manage elk in the same area?

What I'm seeing proposed in the cwd plan in Wyoming is to focus killing off mule deer, in particular bucks, while completely ignoring elk (or at least no change in harvest).

I'll use unit 7 elk which is the same as deer units 64 and 65 as the example since its a cwd hotspot. It would appear the direction that Wyoming wants to take is to shoot deer until numbers are very low, with concentrating harvest on bucks. Yet, there is essentially an uncontrollable elk herd in there with 30+ calves per 100 cows and a way over objective herd. How is killing off deer, but ignoring elk and doing nothing, going to make things better?

I'm having a hard time with getting behind the GF recommendations when they tell me things like, "we have essentially no buck mule deer over 4 years old due to cwd". I know that's not true, I see older bucks in cwd units all the time and for the record, how are they even making the determination on a bucks age without either capturing it as a fawn or tooth cementum? Yeah, they can look at harvested deer, but in nearly every hunting unit on planet earth, harvest is always skewed toward younger bucks. That doesn't mean that there are no bucks living to older age, or that they cant if they weren't killed before they get there. During classifications, they simply cannot determine age based on anything but a wild assed guess to make the statement they have no bucks over 4 years old.

Not seeing the logic in their recommendations, at all.

 

[Hunting Wife]

So with that thought in mind, assuming that cwd strains cross between deer and elk...how would managing cwd be at all practical to focus on mule deer while ignoring and doing nothing to manage elk in the same area?

What I'm seeing proposed in the cwd plan in Wyoming is to focus killing off mule deer, in particular bucks, while completely ignoring elk (or at least no change in harvest).

I'll use unit 7 elk which is the same as deer units 64 and 65 as the example since its a cwd hotspot. It would appear the direction that Wyoming wants to take is to shoot deer until numbers are very low, with concentrating harvest on bucks. Yet, there is essentially an uncontrollable elk herd in there with 30+ calves per 100 cows and a way over objective herd. How is killing off deer, but ignoring elk and doing nothing, going to make things better?

I'm having a hard time with getting behind the GF recommendations when they tell me things like, "we have essentially no buck mule deer over 4 years old due to cwd". I know that's not true, I see older bucks in cwd units all the time and for the record, how are they even making the determination on a bucks age without either capturing it as a fawn or tooth cementum? Yeah, they can look at harvested deer, but in nearly every hunting unit on planet earth, harvest is always skewed toward younger bucks. That doesn't mean that there are no bucks living to older age, or that they cant if they weren't killed before they get there. During classifications, they simply cannot determine age based on anything but a wild assed guess to make the statement they have no bucks over 4 years old.

Not seeing the logic in their recommendations, at all.

I get what you are saying. Do you happen to know prevalences in both deer and elk in the units you mentioned?

My WAG is they will say it’s based on those. If prevalence in elk is low (generally true across the board for as yet poorly understood reasons, but possibly related to that strain issue), and prevalence in mule deer bucks is high (also generally true across the board), managing the elk herd isn’t as much of a concern for them if their goal is just to reduce prevalence. Not advocating a position here, just a guess based on no data whatsoever. However, I’m also familiar with Wyoming’s head-in-the-sand approach when it comes to elk and disease.

 

[Sytes]

It would help, immensely, if citations to real research publications were provided. A lot of this is completely new to me. Thus, I'm pretty skeptical of many, many of the claims here.

From all around the table... I agree. The main area of interest to my internet forum seat, the soil and plant reservoir time frame.

Edit added:
One recent study shared the following;

The findings suggest that soil organic material degrades chronic wasting disease prions. Incubation of chronic wasting disease prions with high concentrations of humic acids decreased both the chronic wasting disease prion signal and infectivity in mice, whereas lower levels of humic acids did not significantly impact protein stability or infectivity. According to the authors, the study provides new insights into soil-prion interactions, the persistence of prions in soil, and their bioavailability to grazing animals.

Soil compound fights chronic wasting disease

A major compound in soil organic matter degrades chronic wasting disease prions and decreases infectivity in mice, according to a new study.

www.sciencedaily.com

Ya, I know... Not the actual though excerpts from the study shared via Science Daily

 

[SAJ-99]

Those new transgenic mouse models are enabling them to really start getting at some of these differences.

That is definitely a positive and probably where the solution will come from. It speeds scientists' ability to test new ideas. The ultimate end result may be just an extending of the incubation period. Would anyone notice if it took 7-10 years from infection to death? Probably not.

Side question, some of data in the WY CWD plan showed very high rates of infection in the samples (30-40%). Did the state (or CO or WI or any other state) see massive natural CWD die offs in those areas (or any other area)?

 

[BuzzH]

I get what you are saying. Do you happen to know prevalences in both deer and elk in the units you mentioned?

My WAG is they will say it’s based on those. If prevalence in elk is low (generally true across the board for as yet poorly understood reasons, but possibly related to that strain issue), and prevalence in mule deer bucks is high (also generally true across the board), managing the elk herd isn’t as much of a concern for them if their goal is just to reduce prevalence. Not advocating a position here, just a guess based on no data whatsoever. However, I’m also familiar with Wyoming’s head-in-the-sand approach when it comes to elk and disease.

IRRC, elk prevalence is about 3-5%, deer is considerably higher maybe 30%? The other big problem I'm having is that within their own proposals, it states that in most areas with the highest prevalence, they are seeing either no increase or in some cases a decrease in prevalence.

Even then I question the way they determine prevalence, its from harvested deer and road kills. In all the literature I've seen cited, deer/elk with cwd are much more vulnerable to predation, getting hit by cars, and killed by hunters. So, are we over-estimating prevalence based on that? Further, in most hunting areas, harvest is restricted to bucks only for the most part, so are we once again, over-estimating prevalence in bucks compared to does? Finally, if the disease is spread by contact with infected animals, I would think that does are in contact with each other (fawns, being in small groups, etc.) more so than bucks that often are loners. I don't understand why bucks would be more likely to have the disease than does, unless its something to do with genotype or some other factor. It cant be just about coming into contact with other deer.

It seems to me like the current course of action being proposed by the WGF is to throw a bunch of shit on the wall and see if anything sticks. There is an undue amount of pressure, coming from somewhere to "do something". IME, never a good idea.

I also understand that at some point we do have to start trying management or we wont continue to learn. However, IMO, because of so many unanswered questions, I'm not comfortable with the draconian measures focused on killing off mule deer, and bucks in particular. It seems like the reasons for taking that approach is because its the easiest thing to sell to a hunting public that is only too eager to kill off mature bucks in the rut. For these reasons, I'm not comfortable, at all, with the current proposals at this time.

 

[TheJason]

It seems to me like the current course of action being proposed by the WGF is to throw a bunch of shit on the wall and see if anything sticks. There is an undue amount of pressure, coming from somewhere to "do something". IME, never a good idea.

I also understand that at some point we do have to start trying management or we wont continue to learn. However, IMO, because of so many unanswered questions, I'm not comfortable with the draconian measures focused on killing off mule deer, and bucks in particular. It seems like the reasons for taking that approach is because its the easiest thing to sell to a hunting public that is only too eager to kill off mature bucks in the rut. For these reasons, I'm not comfortable, at all, with the current proposals at this time.

I think your first sentence really hit the nail on the head. Sometimes we feel like we have to do "something" in order to address an issue, although that something may not be a better choice than nothing.

 

[madtom]

I think your first sentence really hit the nail on the head. Sometimes we feel like we have to do "something" in order to address an issue, although that something may not be a better choice than nothing.

True, but sometimes you don’t know the best action until you try some things either. That whole scientific method thing.

A while back, I’d heard about the potential to selectively cull urban deer in a few places where they’re abundant and cwd prevalence is high to see what effect it would have on future prevalence. Don’t know what came of that, but it seemed like a good idea with potentially less risk if going scorched earth is the wrong choice.

 

[Hookedonelk]

Grooming, birthings, mating, feces, urine, saliva, decomposition due to wounding losses, car kills, predation, natural death, ag crops causing congregation, mast trees causing congregation, winter yarding causing congregation all take place 24/7/365 and contribute to infected deer shedding prions into the environment and eclipse the short term window of baiting/feeding. Its a blip in the year. Baiting did not create CWD nor will a ban of it stop/halt/slow CWD. Its been proven in WI. In the counties with the highest CWD infection rate Baiting is banned for more than 15 years and is having no effect on stopping CWD yet in the part of WI that still allows baiting, CWD has not been found. Banning Baiting is a instant gratification (feel good) measure that tricks the public into thinking the State is taking action then its having zero impact AND SOME DATA SHOW CWD INCREASING WITHOUT BAIT (GASP). But bait piles have been replaced with bait plots which are in the same place year after year after year so congregate deer to the same soils.



Thats the point I was making. Yes.



That was the WI Plan and looks like the MI plan. State agencies thought and think it can be shot away. That is why WI had "ERRADICATION zones" WI had DEZ (Deer Eradication Zones) Once the plan was slayed out to the public and a rebellion took place, they swapped the "D" of deer with "disease" . We laughed.



Until you read the part about infected soils and plant uptake making infected deer no essential to spread.



Yes, human are arrogant and think we can solve this in a wild free ranging herd that migrates. We are funny like that.



Cervid farmers. They are the best friend of making progress in a solution to CWD. They are and will continue funding CWD research as it is their business. It effects their bottom line so like any high dollar business with a problem, they are working for a solution. Remember, this is a transmissible disease in a wild, free ranging and migrating population that sheds into the environment and that shedding boosts the infectious agent.

From a fellow Wisconsin resident that lives in a no baiting area and hunt in several no baiting areas, I do not agree or disagree with the statement that baiting or not baiting affects CWD. However I do not agree with saying that Wisconsin tried the baiting ban in higher concentrated areas and it didn’t help. I say this because every gas station or bait shop in Wisconsin sells corn by the #50 bag, watched 8 skids get delivered to a sporting goods store in a non baiting area the weekend before gun season and it was all sold by thanksgiving. With seeing that and for the people oblivious enough to believe just because it is illegal to bait in these units that people are abiding by it, they should start buying preference points for red and grey squirrels because we are gonna have some good hunting in the next couple years for the amount of corn these squirrels must be eating!!

 

[TheJason]

True, but sometimes you don’t know the best action until you try some things either. That whole scientific method thing.

A while back, I’d heard about the potential to selectively cull urban deer in a few places where they’re abundant and cwd prevalence is high to see what effect it would have on future prevalence. Don’t know what came of that, but it seemed like a good idea with potentially less risk if going scorched earth is the wrong choice.

Agreed, although patience and restraint while waiting for the science to point us where to go is difficult.

Not sure what the answer is.

 

[Carl 9.3x62]

Theoretical situation: if somehow we proved without a sliver of doubt that CWD could in fact NOT be transmitted to humans in any possible way, would it still be as big of a concern that is is now?

 

[JM77]

Agreed, although patience and restraint while waiting for the science to point us where to go is difficult.

Not sure what the answer is.

I'm not sure of the answer either, but in my experience, where I saw "wasters" in the late 90s and early 2000s, I don't see them anymore. We haven't had a positive test off our property in more than a decade and all have been taken from mature bucks over 4 years old. This idea of killing off deer to look like we are doing something, is flat wrong.

 

[Hunting Wife]

IRRC, elk prevalence is about 3-5%, deer is considerably higher maybe 30%? The other big problem I'm having is that within their own proposals, it states that in most areas with the highest prevalence, they are seeing either no increase or in some cases a decrease in prevalence.

Even then I question the way they determine prevalence, its from harvested deer and road kills. In all the literature I've seen cited, deer/elk with cwd are much more vulnerable to predation, getting hit by cars, and killed by hunters. So, are we over-estimating prevalence based on that? Further, in most hunting areas, harvest is restricted to bucks only for the most part, so are we once again, over-estimating prevalence in bucks compared to does? Finally, if the disease is spread by contact with infected animals, I would think that does are in contact with each other (fawns, being in small groups, etc.) more so than bucks that often are loners. I don't understand why bucks would be more likely to have the disease than does, unless its something to do with genotype or some other factor. It cant be just about coming into contact with other deer.

It seems to me like the current course of action being proposed by the WGF is to throw a bunch of shit on the wall and see if anything sticks. There is an undue amount of pressure, coming from somewhere to "do something". IME, never a good idea.

I also understand that at some point we do have to start trying management or we wont continue to learn. However, IMO, because of so many unanswered questions, I'm not comfortable with the draconian measures focused on killing off mule deer, and bucks in particular. It seems like the reasons for taking that approach is because its the easiest thing to sell to a hunting public that is only too eager to kill off mature bucks in the rut. For these reasons, I'm not comfortable, at all, with the current proposals at this time.

Would be really interesting to see population data along with those prevalences. Population stabilizing and/or decreasing at the same time? Not expecting you to answer that...just tickles my brain.

Another hypothesis for why prevalence is higher in bucks is that they roam farther and have more opportunity to be exposed to contaminated environments. I’ve seen no studies that have proven that link though. Not something that’s easy to test in a wild population.

Overestimation is a possibility for all the reasons you mention. Although some people hypothesize that sick deer are less active and thus are less likely to be seen and harvested by hunters so hunter-harvest underestimates CWD prevalence. The only paper I’ve seen on CWD sampling bias:

https://cpw.state.co.us/Documents/Hunting/BigGame/CWD/PDF/ResearchArticles/Detection_of_Bias_JWD.pdf

Regardless, I don’t think blanket hammering of mule deer bucks everywhere is wise or justifiable at this point. But based on the prevalence data we do have, from a lot of places, it seems like there might be something there. I do wish we would have the courage to actually try it somewhere and I’m talking for long enough to actually evaluate it, not just a couple years until people cry enough to make it stop. At least then we could honestly say either yay or nay and go from there.

 

[TheJason]

I'm not sure of the answer either, but in my experience, where I saw "wasters" in the late 90s and early 2000s, I don't see them anymore. We haven't had a positive test off our property in more than a decade and all have been taken from mature bucks over 4 years old. This idea of killing off deer to look like we are doing something, is flat wrong.

So did you have deer you harvested test positive in the past? Was there any significant change in management over the past couple of decades?

 

[JM77]

So did you have deer you harvested test positive in the past? Was there any significant change in management over the past couple of decades?

Yes, we had positive tests in the past on top of the obvious deer in the final stages of the disease we observed or found dead.

The change in management was no hunting and removing salt licks, we had few older bucks available to hunt anyway. In the last 6-7 years, the mature bucks began returning in the herd and we have been harvesting one or so a year since.

 

[TheJason]

Yes, we had positive tests in the past on top of the obvious deer in the final stages of the disease we observed or found dead.

The change in management was no hunting and removing salt licks, we had few older bucks available to hunt anyway. In the last 6-7 years, the mature bucks began returning in the herd and we have been harvesting one or so a year since.

Thanks Jeff. That's interesting. How many years since the last positive?

 

[Trial153]

No surprise your pro baiting and pro deer farms. Considering you use both.