WildWill
Well-known member
I'll never understand the"lets kill them all to save them" mentality. More deer herds have been destroyed by wildlife departments in the name of cwd then by the actual disease with very little to show for it.
MT CWD positive?
- Thread starter Bambistew
- Start date
Hunting Wife
Well-known member
I think that depends on where you are in the epidemiological progression.
Early on, before the disease is endemic and there are few positives and little accumulation of prions in the environment, removing positives would likely have a positive effect. But you would have to do it in perpetuity, as far as we know right now. There is no known way to go the other direction-once it’s there, in the environment and causing infections it’s there for good.
When you have endemic disease, double-digit prevalences, and neighboring areas with even higher double-digit prevalences, shooting more deer probably isn't doing anything. What difference does it make when new infections are being acquired from the environment, and the removed positives are just replaced by new ones from the neighboring high-prevalence population? Maybe you can slow the increase in prevalence for a while (while being relative…it’s a chronic disease after all) but over time that environmental factor is going to win. Shoot them all to zero and you still can’t undo that, as far as we know.
My personal belief is that much of Montana is beyond population management having much impact. It’s too late, again.
Prevalence increases as age increases, likely because the longer you live, the more exposure and opportunities to get infected you have.
But I suspect that the higher the overall prevalence gets, and the higher environmental contamination gets, the less time will be required to get infected. Infections will happen younger and younger as the opportunities for exposure increase.
brocksw
Well-known member
South Korea has been working double time on environmental remediation methods because of their limited surface area to work with. The way I understand it, they’ve made some really good progress, but it’s not easy. Their focus is on small farm raised elk facilities and I haven’t seen anything feasible or practical on large open landscapes. Believe it or not, there are lots of folks working very hard towards solutions. Just not happening fast.
Are there any papers available that make an attempt to quantify environmental prion prevalence and environmental infection rates? It seems to me that environmental prevalence would have to be very high to maintain infection in a herd if you were otherwise able to remove other sources of infection.
brocksw
Well-known member
Not sure if these necessarily answer your question, but may provide a little insight.
I spoke with Dr. Kreeger who led the study linked below. In this study they captured 39 naive elk and placed them in .2 hectare holding pens, all of which held CWD infected elk previously. These elk ate and drank out of the same containers that the previously CWD positive animals did. All 39 elk obtained CWD and 37 of the 39 died between 2009 and 2012. 2 elk died from CWD after the study concluded (2014). As the research suggests, elk generally seem to do better with CWD in terms of length of incubation. But without artificial inoculation of any kind, all 39 elk got the disease and subsequently died from it.
https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES14-00013.1
In the study below they were able to infect deer, solely by environmental exposure. So, no inoculation or "Frankenstein" inoculation.
"The two animals in this cohort were exposed to daily introductions of feed buckets, water, and bedding removed from pens housing deer transitioning from pre-clinical to clinical phases of the disease (Table 1, 2). One of 2 exposed deer became tonsil biopsy PrP D-positive at 15 months pi. At study termination, 19 months pi, both animals were CWD+"
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0005916
"Under experimental conditions, mule deer (Odocoileus hemionus) became infected in two of three paddocks containing naturally infected deer, in two of three paddocks where infected deer carcasses had decomposed in situ ˜1.8 years earlier, and in one of three paddocks where infected deer had last resided 2.2 years earlier. Indirect transmission and environmental persistence of infectious prions will complicate efforts to control CWD and perhaps other animal prion diseases."
"Mule deer exposed to contaminated environments or to infected deer contracted CWD (Table). None of the unexposed deer were infected. One or more introduced deer became infected in two of three paddocks containing a naturally infected deer, in two of three paddocks containing a decomposed deer carcass, and in one of three paddocks contaminated with residual deer excreta (Table) within 1 year of exposure."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323154/
There’s other studies out there showing the same, but these are some I had saved and could copy and paste.
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brocksw
Well-known member
There’s also been some work done to show that orally inoculated animals shed excreta with the same infectivity or greater than those inoculated with brain matter or intracranially.
Some additional work that shows the longer the animal is positive, the more infection material they shed.
Those studies I linked above show that animals can be infected both through environmental exposure and direct/indirect contact. The consensus is the longer they’re exposed the more it will spread through the animals.
Another study done by Ed Hoover shows they can orally inoculate animals with 100-300 nanograms of infectious material diluted into saliva at 10 ml iirc. For scale, 100 ng=1/10,000,000th of a gram.
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brocksw
Well-known member
Efforts towards detecting prions in the environment, to my understanding, has really only happened relatively recently with newer technology. @Hunting Wife might be able to speak more intelligently to the differences and tech.
There’s some more work being done by MNPRO with their RT-quic assays (or maybe it’s the MN-quic?), but that study has not been published yet. But in that study they can detect prions on surfaces and in, *gasp (clutch your pearls!) feeders and bait piles!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931637/
There’s some more work being done by MNPRO with their RT-quic assays (or maybe it’s the MN-quic?), but that study has not been published yet. But in that study they can detect prions on surfaces and in, *gasp (clutch your pearls!) feeders and bait piles!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931637/
Also the prions are maintained in the dirt and feed as mentioned in the studies above.
So when are they going to start limiting farmers from moving unwashed equipment, and selling hay from infected areas to areas not infected?
CWD in the Dakotas and Montana can probably be traced genetically back to WI. During the bad drough year 5-6yrs ago WI was sending massive amounts of hay to those areas and guess what it all came from CWD positive areas.
I spoke to a local processor friend and he said he had 3 guys flat out tell him they wanted the deer tested bc they knew it would be positive, (every deer they have shot the last 3 years has been) and they wanted their second buck tag. Get to keep the antlers here.
We've been dealing with CWD here for almost 20yrs testing rates just keep going down as hunters realize what the DNR is trying to do. And I haven't seen any uptick in people coming into our hospital with any brain eating disease processes. And people are eating deer I would assume would test positive.
As I have started to say when talking about this, I've seen it play out for 20yrs here and it's almost comical bc every state that gets this "new" disease goes through the same steps WI did starting 20yrs ago. Atleast if you are going to try and fight something be innovative about it. But you guys do you and I hope it works out for you.
So when are they going to start limiting farmers from moving unwashed equipment, and selling hay from infected areas to areas not infected?
CWD in the Dakotas and Montana can probably be traced genetically back to WI. During the bad drough year 5-6yrs ago WI was sending massive amounts of hay to those areas and guess what it all came from CWD positive areas.
I spoke to a local processor friend and he said he had 3 guys flat out tell him they wanted the deer tested bc they knew it would be positive, (every deer they have shot the last 3 years has been) and they wanted their second buck tag. Get to keep the antlers here.
We've been dealing with CWD here for almost 20yrs testing rates just keep going down as hunters realize what the DNR is trying to do. And I haven't seen any uptick in people coming into our hospital with any brain eating disease processes. And people are eating deer I would assume would test positive.
As I have started to say when talking about this, I've seen it play out for 20yrs here and it's almost comical bc every state that gets this "new" disease goes through the same steps WI did starting 20yrs ago. Atleast if you are going to try and fight something be innovative about it. But you guys do you and I hope it works out for you.
@brocksw & @Hunting Wife hasn't there been studies that show that some ungulates no matter how much exposure are immune to CWD? Around us it seems to be self limiting and isn't killing off deer herds.
Down in the southern part of the state ground zero for CWD as we know it now. The herds of deer a flourishing even with crazy high positive cases.
Also thanks to the both of you for the studies you posted always interesting to read the new stuff coming out, albeit slowly.
Down in the southern part of the state ground zero for CWD as we know it now. The herds of deer a flourishing even with crazy high positive cases.
Also thanks to the both of you for the studies you posted always interesting to read the new stuff coming out, albeit slowly.
brocksw
Well-known member
Prions don’t have genetics. North Dakota got it from South Dakota and Sask, Montana got it from Saskatchewan and Wyoming.
Wisconsin has been an example of what not to do, react very slowly, be inconsistent with your approach, and pay Dr. Deer 125k for a “plan” when all he did was instill distrust in the actual experts.
But, then again you already sound like one of those folks who knows everything about everything, especially something you obviously understand very little.
I am trying to learn about it and do know a fair amount about it. But I see what kind of person you are sorry for asking you for information to further my knowledge I will stick with asking @Hunting Wife atleast her responses are aimed at education not slamming others who question you.
Thanks for the reply tho. I should've learned from watching you respond in the ND thread have a great day and hope MT shoots all their deer and elk get rid of this big bad disease. Save us all.
brocksw
Well-known member
Youre right, I was being snarky. I apologize. But I’ve seen your attitude towards this before and it’s part of the problem. You laugh off management attempts and you make incorrect assertions like you know them to be fact. It might not seem like it, but that does damage. Misinformation spreads like wildfire and causes a lot of problems. We have a whole FB page here in ND devoted to spreading misinformation.
If you had a single clue what I had to put up with in our issue in ND, you’d be a lot more understanding of why I get a little sharp on this topic. Your wife/Gf ever been afraid to answer a knock at the door?
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brocksw
Well-known member
I think it would be inaccurate to say “no matter how much exposure”. There’s polymorphisms that show decreased susceptibility yes, but once they get it they can still spread it, they still die from it, there’s no such thing(that’s been found yet) as complete resistance. However, I believe there have been a handful of animals, like literally just a few examples, of animals that don’t pick it up in studies or other situations.
That’s some of the best whitetail habitat in the world, so this allows a large population with great fecundity to out breed the negative affects of the disease.
I have yet to see a single study that doesn’t show significant increased mortality and population effects. If someone has it, please share. The closest I’ve seen to that is a herd in CO. But they curtailed hunting to get the population to stabilize.
In terms of “self-limiting”, I’m not sure that’s a correct term to use. I think there’s a lot of variables that come into play, habitat and reproduction dynamics contribute to that. But I’ve seen and heard, even on this forum, personal testimonies from people in Sask and CO who have noticed significant declines in deer population in endemic areas.
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brocksw
Well-known member
I am not going to derail this thread like the ND baiting one did by a singular argument between you and another member I forget the kids name you kept calling out.
However, I don't think I've ever had an attitude. I simply put put information I've seen first hand here in WI and show what it leads too. This example in MT of giving out tags for positive deer is one of them.
When discussing the ND thread @Hunting Wife was very polite and I learned alot from her some tact goes along away.
Like I said I am pretty informed about the disease. I wil admit less so the last 2-3years bc as I see it, it has absolutely no bearing on herd health as a whole or quality of meat. That is my personal observation and opinion but is backed up with facts and first hand outcomes.
Like I said you guys do you and I hope you solve this disease and can remove it from your landscape.
WildWill
Well-known member
Not all of that damage and misinformation comes from the public plenty on the biologist side as well.
brocksw
Well-known member
He was a part of the group that had the bill introduced. So was his dad. They made like 170 posts in less than a week. They almost got the bill passed and we had to fight like hell to kill it.
Again, anecdotal observations can be misleading. People in Sask were sayin in the same thing. “I’m not seeing dead deer so it must not be a problem”. Now I’ve talked to a few folks up there who say the age class of deer has gone way down and some of the endemic areas they see a fraction of the deer they used to. Like I said, I know it seems harmless. But this issue is complex and it is ripe with misinformation.
I don't want to downplay your wife/gf feeling unsafe that is BS that someone would make her or anyone feel that way over this topic. But, maybe the last part of your first sentence answers why the 2nd sentence happens?
You came and attacked me right away when I was just asking questions. Not spreading any information questions and observations is all.
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