Friday, September 21, 2012

Chronic Wasting Disease CWD raises concerns about deer farms in Iowa

Updated: 21 September 2012 | 6:30 am

Disease raises concerns about deer farms in Iowa

Most cases found so far in state tied to confined animals

Iowa’s first seven cases of chronic wasting disease — all directly related to confined whitetail deer — have put a bull’s eye on the backs of the state’s deer breeders and the pay-to-shoot facilities they supply.

Critics of penned deer operations — mainly hunters and game managers — say captive deer are more likely than wild deer to spread the always fatal brain disease and that killing penned deer violates the “fair chase” premise that underlies ethical hunting.

“I’ve been crucified and demonized,” said Tom Brakke, a deer breeder and hunting preserve proprietor whose deer have been implicated in five of the state’s seven positive CWD tests.

Tim Powers, field director for the Iowa chapter of Whitetails Unlimited, said many Iowa deer hunters fear that wild deer will soon be infected and resent the role of game farms in the spread of the disease.

Confined deer operations are the “Typhoid Mary of the ungulates,” said Sen. Dick Dearden, D-Des Moines, chairman of the Senate Natural Resources Committee.

Like many other Iowa hunters, Dearden said he thinks the shooting preserves, where people pay to shoot deer in an enclosure, are more trouble and expense than they are worth.

“I don’t understand how people who shoot confined deer would call themselves hunters,” said Dearden, who observed that opposition to hunting penned animals is “probably the only issue that PETA (People for the Ethical Treatment of Animals) and I agree on.”

Iowa recorded its first CWD case in July at the Pine Ridge Hunting Lodge near Bloomfield in Davis County.

The Department of Natural Resources, which regulates hunting preserves, and the Department of Agriculture and Land Stewardship, which regulates breeding facilities, have since confirmed six more positive tests — all but two related to the Davis County hunting preserve and to a Cerro Gordo County deer breeding facility, both owned by Tom and Rhonda Brakke of Clear Lake.

The Clear Lake facility has recorded a positive test, as have three deer raised at that facility and shipped to a combination shooting and breeding facility in Pottawattamie County, according to State Veterinarian David Schmitt.

The other two positive tests at the Pottawattamie facility involved a deer acquired from another Iowa breeder and a deer that was a natural addition to the herd, Schmitt said.

Tom Brakke said no deer have entered his breeding facility in the past 10 years and that his herd — about 500 deer at Clear Lake and more than 150 at the Bloomfield preserve — have been enrolled for the past nine years in a CWD monitoring program under which every deer that dies or is killed is tested for the disease. (story continues below map)

“Nothing comes in 10 years. Every deer that died in the past nine years has been tested. The incubation period for CWD is 48 months. How did I get CWD? That’s what I want to know,” said Brakke, who sees his investment of 20 years and $2.5 million rapidly disappearing.

While hunters worry that Brakke’s deer have already infected or will soon infect wild Iowa deer, it is “most definitely” possible that his deer could have been infected by wild Iowa deer, Brakke said.

Whitetail expert Willie Suchy, leader of the DNR’s wildlife research unit, said CWD is “more likely to show up among captive animals” because they are often moved from one facility to another, increasing their exposure.

Bryan Richards, a disease investigator for the U.S. Geological Survey National Wildlife Health Center in Madison, Wis., said captive and wild deer are equally susceptible to CWD.

Nevertheless, he said, disease outbreaks accelerate in a captive environment.

“You are forcing contact in a pen. A sick animal will soon have contact with every animal in the pen,” he said.

Richards said “there is ample evidence right there in Iowa that CWD moves through game farm enclosures.”

Both Suchy and Richards said managing deer in the CWD era would be greatly simplified and rendered more effective if there were an economical diagnostic test. Today’s standard test is performed post-mortem on brain cells, which can be extracted only from dead animals.

That penned deer are more susceptible than wild deer to chronic wasting disease is a “common misconception,” according to Wayne Johnson of Farley, a member of the Iowa Whitetail Deer Association board of directors.

With CWD confirmed in all of Iowa’s neighboring states, “it was bound to show up in Iowa,” he said.

One reason the disease showed up first among confined deer is that all confined deer in Iowa over the age of 1 are tested for CWD when they die, which compares with a small percent of the wild deer herd, about 1 percent in any given year, according to Iowa Whitetail Deer Association spokesman Scott Kent, who is raising about 250 whitetails on a combined hunting and breeding facility near Osceola.

Johnson, who keeps 13 deer in a 2-acre pen, said he raises whitetails for both fun and profit.

The few that he sells each year go to hunting preserves and bring anywhere from $500 to $5,000 each, depending on the size of their antlers, Johnson said.

Pine Ridge Lodge’s 2011 price list includes whitetail bucks from $3,500 for antlers in the 160 to 169-inch range all the way up to $30,000 for monster bucks with antlers measuring more than 300 inches.

Another common misconception, according to both Brakke and Johnson, is that deer within hunting preserves are easy to shoot.

“They are still a wild animal, and they have a lot of room to run and hide” within a 320-acre enclosure, the minimum size allowed under Iowa law, Johnson said.

“I love to hunt myself, and if it wasn’t a real hunt I wouldn’t do it,” Brakke said.

DNR spokesman Kevin Baskins confirmed that the state’s first CWD-positive deer was shot just two hours after it stepped off the truck, which would not have given the animal much time to acclimate to its new surroundings.

Randy Taylor, chairman of the legislative committee of the Iowa Bowhunters Association, said the organization is concerned that commercial deer operations are threatening the health of Iowa’s wild deer. “We will recommend that the Legislature pass stricter rules governing the operation of deer breeding and shooting facilities,” Taylor said.

Dearden said he is “really looking at” revisiting state rules governing commercial deer operations in the upcoming session of the Legislature.

Although Department of Agriculture and the DNR appear to be working well together, the split jurisdiction is an area of concern, Dearden said.

Brakke’s 330-acre hunting preserve will be depopulated under an agreement with the DNR. The agreement allows Brakke to honor commitments for hunts previously scheduled between Sept. 8 and Dec. 25, said Dale Garner, chief of the DNR’s Wildlife Bureau. Any deer killed during those hunts will be tested for CWD and any remaining after those hunts will be killed and tested for the fatal brain disease, Garner said.

by having the age limit on testing i.e. deer that are 16 months of age or older. it’s well documented that fawns are very susceptible to CWD at a early age, and the logic behind the 16 months of age or older for the testing of any dead deer will only lead to more CWD. it’s like the old flawed surveillance for Creutzfeldt Jakob Disease in the USA, and the threat of proven Iatrogenic spread there from, and then putting a age limit on CJD surveillance of anyone > or equal to 55 years and over, do not have to be reported, however, in the 55 year and older, the CJD infection rate jumps from 1 per 1,000,000 to 1 in 9,000, and the only folks to have been proven to pass the Iatrogenic CJD via tissues and organs are sporadic CJD victims. another example of industry regulations, i.e. BSE testing of cattle only 30 month and older. cattle have been documented with BSE as young as 20 months.

Wisconsin : Six White-Tailed Deer Fawns Test Positive for CWD

Date: May 13, 2003 Source: Wisconsin Department of Natural Resources

Contacts: Julie Langenberg Wildlife Veterinarian 608-266-3143 Tom Hauge Director, Bureau of Wildlife Management 608-266-2193

MADISON -- Six fawns in the area of south central Wisconsin where chronic wasting disease has been found in white-tailed deer have tested positive for the disease, according to Department of Natural Resources wildlife health officials. These are the youngest wild white-tailed deer detected with chronic wasting disease (CWD) to date.

Approximately 4,200 fawns, defined as deer under 1 year of age, were sampled from the eradication zone over the last year. The majority of fawns sampled were between the ages of 5 to 9 months, though some were as young as 1 month. Two of the six fawns with CWD detected were 5 to 6 months old. All six of the positive fawns were taken from the core area of the CWD eradication zone where the highest numbers of positive deer have been identified.

"This is the first intensive sampling for CWD in fawns anywhere," said Dr. Julie Langenberg, Department of Natural Resources wildlife veterinarian, "and we are trying to learn as much as we can from these data".

"One noteworthy finding is simply the fact that we found positive fawns," Dr. Langenberg said. "These results do show us that CWD transmission can happen at a very young age in wild white-tailed deer populations. However, we found that the percentage of fawns infected with CWD is very low, in the area of 0.14 percent. If there was a higher rate of infection in fawns, then fawns dispersing in the spring could be much more worrisome for disease spread."

Dr. Langenberg noted that while the youngest CWD-positive fawns had evidence of disease-causing prions only in lymph node tissue, several of the older CWD-positive fawns had evidence of CWD prions in both lymph node and brain tissues -- suggesting further progression of the disease.

"Finding CWD prions in both lymph and brain tissues of deer this young is slightly surprising," said Langenberg, "and provides information that CWD infection and illness may progress more rapidly in a white-tailed deer than previously suspected. Published literature suggests that CWD doesn't cause illness in a deer until approximately 16 months of age. Our fawn data shows that a few wild white-tailed deer may become sick from CWD or may transmit the disease before they reach that age of 16 months."

One of the positive fawns was shot with a doe that was also CWD positive. Information about these fawn cases combined with will help researchers who are studying the age and routes of CWD transmission in wild deer populations. "More data analysis and ongoing deer movement studies should give us an even better understanding of how this disease moves across the landscape", said Langenberg.

"Thanks to eradication zone hunters who submitted deer of all ages for sampling, we have a valuable set of fawn data that is contributing to our state's and the nation's understanding about CWD," Langenberg said.

> > > Two of the six fawns with CWD detected were 5 to 6 months old. < < <

Why doesn't the Wisconsin DNR want to routinely test fawns ?

The DNR highly discourages the testing of any fawns regardless of where they were harvested. Of the more than 15,000 fawns from the CWD-MZ that have been tested, only 23 were test positive, and most of those were nearly one year old. It is exceedingly unlikely that a deer less than one year old would test positive for CWD, even in the higher CWD prevalence areas of southern Wisconsin. Few fawns will have been exposed to CWD, and because this disease spreads through the deer's body very slowly, it is very rare in a fawn that the disease has progressed to a level that is detectable. This means that testing a fawn provides almost no information valuable to understanding CWD in Wisconsin's deer herd and does not provide information of great value to the hunter in making a decision about venison consumption.

> > > It is exceedingly unlikely that a deer less than one year old would test positive for CWD < < < ???

Chronic Wasting Disease in a Wisconsin White-Tailed Deer Farm

and 15 of 22 fawns aged 6 to 9 months (68.2%) were positive.

specific susceptibility? 194. It is probable, based on age-class specific prevalence data from wild cervids and epidemiological evidence from captive cervids in affected research centres, that both adults and fawns may become infected with CWD (Miller, Wild & Williams, 1998; Miller et al., 2000).

198. In Odocoileus virginianus – white tailed deer, out of 179 white-tailed deer which had become enclosed by an elk farm fence, in Sioux County, northwestern Nebraska, four fawns only eight months old were among the 50% of CWD-positive animals; these fawns were not showing any clinical signs of CWD (Davidson, 2002).


Volume 17 January 2002 Number 4

CWD News from Nebraska and Kansas

Infection with the chronic wasting disease (CWD) agent recently was found in 28 of 58 formerly wild white-tailed deer in a high-fenced enclosure adjacent to a pen containing CWDaffected captive elk in northern Sioux County, Nebraska.

Four of the positive deer were fawns approximately 8 months old, which is unusually young for animals testing positive for CWD.

A January survey of 39 free-ranging deer collected within 15 miles of the positive elk and deer pens detected 8 (20%) infected animals. Test results are pending for additional deer collected inside and outside of the enclosure, and additional surveillance is planned for free-ranging deer in northwestern Nebraska. Previously, CWD had been documented in Nebraska in only two wild mule deer, both of which came from Kimball County in the southwestern panhandle adjacent to the endemic area of northeastern Colorado and southwestern Wyoming.

CWD in adult deer and fawns

A hundred and thirty-three white-tailed deer in the study were killed after CWD was diagnosed in the deer within the fenced area. Paired samples of formalin-fixed tissue for CWD diagnosis and frozen tissue for DNA sequence analysis were collected. Fifty per cent (67/133) of deer were diagnosed with CWD (Table 2) using an immunohistochemical assay for PrPd in formalin-fixed, paraffinembedded brain and lymphoid tissues.

Five of the CWD-positive deer were fawns, less than 1 year of age.

Early CWD (PrPd detected in the tonsil or retropharyngeal node but not brain) was diagnosed in 14 deer (12 adults ranging from 1?5 to more than 5 years of age and two fawns). Late CWD (PrPd detectable in brain as well as lymphoid tissues) was diagnosed in 53 deer (50 adults ranging in age from 1?5 to 7 years of age and three fawns). None of the CWD-positive deer showed clinical signs of the disease (weight loss, hypersalivation, disorientation) or gross changes consistent with CWD (serous atrophy of fat) at necropsy.

Illinois CWD, see where there 2003 sampling showed 2. % of fawns tested had CWD i.e. 1 positive out of 51 samples.


Boone-Winnebago Unit Fawn 51 1 2.0%





For example, in 2008 a fawn tested positive and in 2010 an infected yearling buck was detected in Smith County


Mother to Offspring Transmission of Chronic Wasting Disease

Candace K. Mathiason, Amy V. Nalls, Kelly Anderson, Jeanette Hayes-Klug, Nicholas Haley and Edward A. Hoover Colorado State University, Department of Microbiology, Immunology and Pathology, Fort Collins, CO USA

Key words: Chronic wasting disease, vertical transmission, muntjac deer

We have developed a new cervid model in small Asian muntjac deer (Muntiacus reevesi) to study potential modes of vertical transmission of chronic wasting disease (CWD) from mother to offspring. Eight of eight (8/8) muntjac doe orally infected with CWD tested PrPCWD lymphoid positive by 4 months post infection. Six fawns were born to these CWD-infected doe. Six fawns were born to 6 CWD-infected doe; 4 of the fawns were non-viable. The viable fawns have been monitored for CWD infection by immunohistochemistry and sPMCA performed on serial tonsil and rectal lymphoid tissue biopsies. PrPCWD has been detected in one fawn as early as 40 days of age. Moreover, sPMCA performed on rectal lymphoid tissue has yield positive results on another fawn at 10 days of age. In addition, sPMCA assays have also demonstrated amplifiable prions in maternal placental (caruncule) and mammary tissue of the dam. Additional pregnancy related fluids and tissues from the doe as well as tissue from the nonviable fawns are currently being probed for the presence of CWD. In summary, we have employed the muntjac deer model, to demonstrate for the first time the transmission of CWD from mother to offspring. These studies provide the foundation to investigate the mechanisms and pathways of maternal prion transfer.

"PrPCWD has been detected in one fawn as early as 40 days of age. Moreover, sPMCA performed on rectal lymphoid tissue has yield positive results on another fawn at 10 days of age"

Oral transmission and early lymphoid tropism of chronic wasting disease PrPres in mule deer fawns (Odocoileus hemionus)

The rapid infection of deer fawns following exposure by the most plausible natural route is consistent with the efficient horizontal transmission of CWD in nature and enables accelerated studies of transmission and pathogenesis in the native species. Introduction

Wisconsin is home to about 500 deer farmers, and there are more than 8,000 farms in the U.S., according to Laurie Seale of Gilman, who's president of Whitetails of Wisconsin.

snip...please see full text ;

Saturday, February 04, 2012

Wisconsin 16 MONTH age limit on testing dead deer Game Farm CWD Testing Protocol Needs To Be Revised

Monday, June 11, 2012

OHIO Captive deer escapees and non-reporting

Tuesday, September 11, 2012

Agreement Reached with Owner to De-Populate CWD Deer at Davis County Hunting Preserve Iowa

Wednesday, September 05, 2012

Additional Facility in Pottawatamie County Iowa Under Quarantine for CWD after 5 deer test positive

Friday, July 20, 2012

CWD found for first time in Iowa at hunting preserve

Tuesday, June 05, 2012

Captive Deer Breeding Legislation Overwhelmingly Defeated During 2012 Legislative Session

Saturday, September 01, 2012

Resistance of Soil-Bound Prions to Rumen Digestion

Friday, August 31, 2012


Saturday, June 09, 2012

USDA Establishes a Herd Certification Program for Chronic Wasting Disease in the United States

*** 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.



Wednesday, February 16, 2011




PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer

Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA

PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)

Thursday, May 31, 2012

CHRONIC WASTING DISEASE CWD PRION2012 Aerosol, Inhalation transmission, Scrapie, cats, species barrier, burial, and more

Monday, September 17, 2012

Rapid Transepithelial Transport of Prions Following Inhalation

GAME FARMERS, CWD, AND THEIR COMMENTS...disturbing...frightening even. it seems they are oblivious to their own demise. ...

see comments ;

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). 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).


Saturday, February 18, 2012

Occurrence, Transmission, and Zoonotic Potential of Chronic Wasting Disease

CDC Volume 18, Number 3—March 2012

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).

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

The overall diagnostic specificity was 99.8%. Selective use of antemortem rectal biopsy sample testing would provide valuable information during disease investigations of CWD-suspect deer herds.



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