Chronic Wasting Disease: CWD found in wild deer, elk Saskatchewan a slowly spreading epidemic there'll be no stopping it the longer we wait

CWD found in wild deer, elk

By Betty Ann Adam, The StarPhoenix

A "slowly spreading epidemic" of chronic wasting disease threatens deer and elk populations in Saskatchewan.

Meanwhile, fewer hunters are sending animal heads for testing and federal funding for research into the disease was eliminated last year.

"From the data that we do have, it's quite astonishing ... This disease is on the march in a major way," said Ted Leighton, executive director of the Canadian Co-operative Wildlife Health Centre at the University of Saskatchewan college of veterinary medicine.

"This is getting to levels where we can start to be concerned about actual effects on wild deer populations," he said.

In February, a yearling elk found dead in a Nipawin farmyard was the first wild elk in the province to test positive for CWD.

The disease has been tracked among farmed elk populations for a number of years.

Between 13 and 24 per cent of a small sample of wild cervids (deer and elk) tested in the Nipawin area northeast of Prince Albert have been found to have CWD. It has also been found in a moose in Alberta, and experiments have shown it can be transmitted to caribou, though none have been found in the wild.

The disease is caused by little-understood agents, called prions, that attack the brain and cause death.

Prions also cause bovine spongiform encephalopathy, commonly known as mad cow disease in cattle and Creutzfeldt-Jakob disease in humans.

Higher rates of CWD infection are found in cervids along the South Saskatchewan River toward the Alberta border, where it has been studied the most intensively, Leighton said.

"The tools we have to find and understand how prions are transmitted among animals and in environments are no way near as well-developed as with a lot of other disease-causing agents. So we have a hard time studying this disease," he said.

It can be transmitted directly between animals and through the environment, when infected animals contaminate their environment with a lot of abnormal prion protein, which persists for a very long time in nature.

Scientists are concerned that Saskatchewan is developing highly-contaminated environments or large proportions of herds that are infected and transmitting it to each other, he said.

An important part of studying the disease is keeping track of how many animals are infected, but fewer hunters have been giving heads to conservation officers in recent years, decreasing researchers' ability to quantify the problem accurately.

Leighton urges hunters to give conservation officers their animal heads and report sick or dead deer they encounter.

Members of the public can also support research into the disease by contacting their elected representatives or organizations like the Saskatchewan Wildlife Federation, Leighton said. Federal funding for CWD research was eliminated last year.

PrioNet Canada was an important network centre of excellence and a major sponsor of CWD research in Saskatchewan for seven years, but its application for further funding was rejected last year. That leaves the Alberta Prion Research Institute as the only large project looking into the disease, Leighton said.

"The (two projects) worked very closely together. It was a great partnership - one provincial, one federal. They really made huge, huge, giant steps forward in our understanding of prion disease, and now half of that's gone, the federal half," Leighton said.

The Canadian Food Inspection Agency has a small laboratory that does some work on CWD, but only for game-ranched animals. It does not participate in monitoring programs.

The disease slowly kills animals, shortening females' reproductive lives, and will eventually cause numbers to drop. If the number of fawns that survive to become reproducing adults drops to less than one per female, "there'll be no stopping it the longer we wait, not that we know how to stop it now," Leighton said.

Research needs to be maintained, and it will take time for current research to translate into new tools for trying to reduce the impact of the disease, he said.

badam@thestarphoenix.com

http://www.thestarphoenix.com/health/found+wild+deer/8117830/story.html

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"This is getting to levels where we can start to be concerned about actual effects on wild deer populations," he said.

In February, a yearling elk found dead in a Nipawin farmyard was the first wild elk in the province to test positive for CWD.

The disease has been tracked among farmed elk populations for a number of years.

The disease is caused by little-understood agents, called prions, that attack the brain and cause death.

Prions also cause bovine spongiform encephalopathy, commonly known as mad cow disease in cattle and Creutzfeldt-Jakob disease in humans.

Higher rates of CWD infection are found in cervids along the South Saskatchewan River toward the Alberta border, where it has been studied the most intensively, Leighton said.

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very disturbing...tss

Wednesday, December 05, 2012

CANADA CWD VOLUNTARY HERD CERTIFICATION PROGRAM 2012-12-05 Accredited Veterinarian's Manual / Manuel du vétérinaire accrédité

http://chronic-wasting-disease.blogspot.com/2012/12/canada-cwd-voluntary-herd-certification.html

Thursday, November 29, 2012

Chronic wasting disease on the Canadian prairies

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This apparent apathy comes at a time when evidence is accumulating that CWD will cause population declines and altered age structures. In the only population of free-ranging deer in Canada being closely monitored for changes in CWD prevalence and survival, we estimate CWD prevalence in adult deer is now approximately 50% and is the main cause of mortality in adult deer. The study area is immediately adjacent to one of the first elk farms to test positive for CWD and it is likely that close to 15 years of infection in this wild population has resulted in ever increasing environmental burdens of prions which is now driving the outbreak. Detailed radio-tracking and motion sensitive photography is showing that mule deer in this area repeatedly and heavily use anthropogenic sites such as leaking grain bins, cattle salt blocks, hay bales, etc. Increased congregation and contamination of these sites with urine, saliva and feces increases the risk of CWD transmission. In essence these wild deer are behaving similar to deer on game farms except their movement isn’t constrained by a fence. The outcome is likely to be the same, extremely high infection rates and drastic population declines. ...

snip...

http://chronic-wasting-disease.blogspot.com/2012/11/chronic-wasting-disease-on-canadian.html

Because of their close taxonomic relationship and similarities in DNA sequences of the prion protein (PrP) coding region to deer and wapiti, it had been hypothesized that moose (Alces alces shirasi) would be naturally susceptible to infection if sufficient exposure to the CWD agent occurred (Williams, 2005).

A recent experiment using oral exposure to infectious brain tissue in captive moose confirmed that this species is susceptible to CWD (Kreeger et al., 2006). Here, we report a natural case of CWD in a free-ranging moose from north central Colorado.

http://www.jwildlifedis.org/content/43/2/309.long

Anim Genet. 2006 August; 37(4): 425–426. doi: 10.1111/j.1365-2052.2006.01466.x PMCID: PMC1592321

Polymorphisms of the prion protein gene (PRNP) in Alaskan moose (Alces alces gigas)

“Genetic similarities, susceptibility in the laboratory setting and overlapping geographical ranges suggest the lack of a barrier to the transmission of prion disease from mule and white-tailed deer to moose.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1592321/

how many states have $465,000., and can quarantine and purchase there from, each cwd said infected farm, but how many states can afford this for all the cwd infected cervid game ranch type farms ???

? game farms in a state X $465,000., do all these game farms have insurance to pay for this risk of infected the wild cervid herds, in each state ???

Tuesday, December 20, 2011

CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm Update DECEMBER 2011

The CWD infection rate was nearly 80%, the highest ever in a North American captive herd.

RECOMMENDATION: That the Board approve the purchase of 80 acres of land for $465,000 for the Statewide Wildlife Habitat Program in Portage County and approve the restrictions on public use of the site.

Form 1100-001

(R 2/11)

NATURAL RESOURCES BOARD AGENDA ITEM

SUBJECT: Information Item: Almond Deer Farm Update

FOR: DECEMBER 2011 BOARD MEETING

TUESDAY

TO BE PRESENTED BY TITLE: Tami Ryan, Wildlife Health Section Chief

SUMMARY:

http://dnr.wi.gov/about/nrb/2011/december/12-11-2b2.pdf

http://chronic-wasting-disease.blogspot.com/2011/12/chronic-wasting-disease-cwd-wisconsin.html

*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.

http://collections.europarchive.org/tna/20080102193705/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf

2011

*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.

http://www.usaha.org/Portals/6/Reports/2011/report-cwal-2011.pdf

SEE MORE USAHA REPORTS HERE, 2012 NOT PUBLISHED YET...TSS

http://www.usaha.org/Portals/6/Proceedings/USAHAProceedings-2010-114th.pdf

http://www.usaha.org/Portals/6/Proceedings/2009_USAHA_Proceedings.pdf

http://portals5.gomembers.com/portals/6/proceedings/2008_usaha_proceedings.pdf

Tuesday, June 05, 2012

Captive Deer Breeding Legislation Overwhelmingly Defeated During 2012 Legislative Session

http://chronic-wasting-disease.blogspot.com/2012/06/captive-deer-breeding-legislation.html

Friday, August 31, 2012

COMMITTEE ON CAPTIVE WILDLIFE AND ALTERNATIVE LIVESTOCK and CWD 2009-2012 a review

http://chronic-wasting-disease.blogspot.com/2012/08/committee-on-captive-wildlife-and.html

Friday, August 24, 2012

Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting disease within white-tailed deer (Odocoileus virginianus) herds in North America

http://chronic-wasting-disease.blogspot.com/2012/08/diagnostic-accuracy-of-rectal-mucosa.html

Thursday, March 14, 2013

TEXAS DEER BREEDERS CHEER TWO NEW BILLS SB 1444 AND HB 2092 THAT COULD HELP POTENTIALLY ENHANCE CHRONIC WASTING DISEASE CWD

http://chronic-wasting-disease.blogspot.com/2013/03/texas-deer-breeders-cheer-two-new-bills.html

Tuesday, December 18, 2012

*** A Growing Threat How deer breeding could put public trust wildlife at risk

http://chronic-wasting-disease.blogspot.com/2012/12/a-growing-threat-how-deer-breeding.html

2012 CDC REPORT ON CWD

Volume 18, Number 3—March 2012 Synopsis Occurrence, Transmission, and Zoonotic Potential of Chronic Wasting Disease

snip...

Prevalence and Surveillance

Originally recognized only in southeastern Wyoming and northeastern Colorado, USA, CWD was reported in Canada in 1996 and Wisconsin in 2001 and continues to be identified in new geographic locations (Figure 1, panel A). CWD has been identified in free-ranging cervids in 15 US states and 2 Canadian provinces and in ≈100 captive herds in 15 states and provinces and in South Korea (Figure 1, panel B).

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CWD surveillance programs are now in place in almost all US states and Canadian provinces (Figure 2, panel A). More than 1,060,000 free-ranging cervids have reportedly been tested for CWD (Figure 2, panel B) and ≈6,000 cases have been identified (Figure 2, panel C) according to data from state and provincial wildlife agencies.

snip...

Testing of captive cervids is routine in most states and provinces, but varies considerably in scope from mandatory testing of all dead animals to voluntary herd certification programs or mandatory testing of only animals suspected of dying of CWD.

snip...

Long-term effects of CWD on cervid populations and ecosystems remain unclear as the disease continues to spread and prevalence increases. In captive herds, CWD might persist at high levels and lead to complete herd destruction in the absence of human culling. Epidemiologic modeling suggests the disease could have severe effects on free-ranging deer populations, depending on hunting policies and environmental persistence (8,9). CWD has been associated with large decreases in free-ranging mule deer populations in an area of high CWD prevalence (Boulder, Colorado, USA) (5). In addition, CWD-infected deer are selectively preyed upon by mountain lions (5), and may also be more vulnerable to vehicle collisions (10). Long-term effects of the disease may vary considerably geographically, not only because of local hunting policies, predator populations, and human density (e.g., vehicular collisions) but also because of local environmental factors such as soil type (11) and local cervid population factors, such as genetics and movement patterns (S.E. Saunders, unpub. data).

snip...

Controlling the spread of CWD, especially by human action, is a more attainable goal than eradication. Human movement of cervids has likely led to spread of CWD in facilities for captive animals, which has most likely contributed to establishment of new disease foci in free-ranging populations (Figure 1, panel A). Thus, restrictions on human movement of cervids from disease-endemic areas or herds continue to be warranted. Anthropogenic factors that increase cervid congregation such as baiting and feeding should also be restricted to reduce CWD transmission. Appropriate disposal of carcasses of animals with suspected CWD is necessary to limit environmental contamination (20), and attractive onsite disposal options such as composting and burial require further investigation to determine contamination risks. The best options for lowering the risk for recurrence in facilities for captive animals with outbreaks are complete depopulation, stringent exclusion of free-ranging cervids, and disinfection of all exposed surfaces. However, even the most extensive decontamination measures may not be sufficient to eliminate the risk for disease recurrence (20; S.E. Saunders et al. unpub. data)

http://wwwnc.cdc.gov/eid/article/18/3/11-0685_article.htm