Post on 28-Jan-2018
Chronic Wasting Disease in Free Roaming Cervids in Saskatchewan and Alberta
Submitted to
Eliot Terry
BIO-163 CO-2
Lethbridge Community College
By
Richard Belchamber
November 28, 2006
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Abstract
In North America, elk (Cervus elaphus), mule (Odocoileus hemionus), and white-tailed
deer (Odocoileus virginianus) are dying from chronic wasting disease. Chronic wasting
disease in cervids is the equivalent to Mad Cow Disease in cattle although the form of
transmission is unknown. This disease affects more male deer than female deer and risk
of getting the disease increased with age. There are various signs of the disease in later
stages in infected animals such as drooling, depression, weight loss, disinterest in eating,
and eventual death. The disease was first discovered in a game farm in Colorado in 1967
and has escaped to the free-ranging population and is now found in Wisconsin, Nebraska,
and New Mexico. A separate outbreak (which may or may not have been connected to
the original outbreak) was found in Saskatchewan in an elk farm in 1996. The disease
somehow escaped into the free-ranging population of white-tailed deer and mule deer,
with a lower prevalence found in elk. Recent (2005) collected tests from Saskatchewan
Environment and Wisconsin Department of Natural Resources show an average chance
of getting with chronic wasting disease a deer in Saskatchewan is 0.9% while it is 0.7%
in Wisconsin. In both areas chronic wasting disease has been spreading for the last 5 to 6
years. Chronic wasting disease has been found in deer along the Alberta and
Saskatchewan border in 2006. Alberta has taken an aggressive stance on chronic wasting
disease by setting up herd reduction areas similar to those in Saskatchewan. These areas
are designated for hunter harvest surveillance in order to determine if chronic wasting
disease is spreading.
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Table of Contents
1 Introduction ................................................................................................................. 1
2 What is Chronic Wasting Disease............................................................................... 2
3 History of Chronic Wasting Disease........................................................................... 3
4 Current Plans for Chronic Wasting Disease in Canada .............................................. 5
5 A Comparative Analysis ............................................................................................. 6
5.1 CWD in Saskatchewan ....................................................................................... 7
5.2 CWD in Wisconsin ............................................................................................. 8
5.3 Analysis............................................................................................................... 9
6 CWD in Alberta ........................................................................................................ 10
7 What can Hunters do to Help fight Chronic Wasting Disease.................................. 11
8 Literature Citied ........................................................................................................ 13
9 Appendix A. Herd Reduction Areas and Zones required to deposit samples in
Saskatchewan .................................................................................................................... 17
10 Appendix B. Herd Reduction Zones and Disease Eradication Zones for 2006 in
Wisconsin .......................................................................................................................... 18
Figures and Tables
Table 1. Results of Recent CWD Tests in Saskatchewan ................................................... 7
Table 2. Results of Recent CWD Tests in Wisconsin ........................................................ 8
Figure 1. Locations in North America where CWD has been diagnosed ........................... 4
Figure 2. Percentage of CWD in Free-ranging population in Saskatchewan ..................... 8
Figure 3. Percentage of CWD in Free-ranging population in Wisconsin ........................... 9
Figure 4. CWD Herd Reductions Areas and the Voluntary Deer Head Submission zones
........................................................................................................................................... 10
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1 Introduction
One of the most defining characteristics of the provinces of Saskatchewan and
Alberta are the vast grasslands areas in the south and the boreal forest to the north. In
both these areas a few of the common primary consumers are White-tailed deer
(Odocoileus virginianus), Mule deer (Odocoileus hemionus), and elk (Cervus elaphus)
which all stem from the Family Cervidae. For hundreds of years these animals have been
a keystone for various ecosystems in these two habitats and also an economic tool used
by government agencies and local businesses. These populations of these animals are
now in danger of chronic wasting disease (CWD) which had originally been discovered
in a research laboratory in Colorado in 1967, and has been fairly common in cervids
(members of the Cervidae family) in game farms and has escaped to the free-ranging
population(Miller and Williams 2002).
This disease is very dangerous because it is in the same family of virus as Mad
Cow disease which grew a strain that affects humans, but also because no animal has ever
survived after being diagnosed with the disease, and there are no known tests for CWD
while animals are alive (Miller and Williams 2002, Wisconsin Depart of Natural
Resources 2002). The disease also poses a large threat to local economies and
government agencies. The local ecosystem would be devastated by the lost of the cervids.
Various federal agencies are involved with the eradication and control such as the
Government of Canada, Health Canada, Parks Canada, Canadian Public Health Agency,
the United States Government, American Animal & Plant Health Inspection Service, and
United States Depart of Agriculture. Also various provincial and state agencies such as
Alberta Sustainable Resource Development, Saskatchewan Environment, and the
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Wisconsin Department of Natural Resources among others. And there are independent
researchers such as M.W. Miller, E.S. Williams, E.M. Schauber, A. Woolf, DA Grear
MD Samuel, J.A. Langenberg, and K. Delwyn as well as many others. And various non-
profit organizations like the Chronic Wasting Disease Alliance.
The aim of this paper is identify what CWD is, examine its history, compare how
it’s being handled in different places, to look where the disease is headed in Canada, and
what people can do to help fight the disease.
2 What is Chronic Wasting Disease
CWD is a transmissible neurological disease found in Cervids. It is classified as a
Transmissible Spongiform Encephalopathy (TSE), it is a disease from the same family as
Mad Cow disease in cattle, scrapie in sheep, and Creutzfeldt - Jakob disease in humans
(Wisconsin Department of Natural Resources 2002). The disease causes prions (proteins)
in the brain to convert brain cells into spongy cells. These cells cause microscopic holes
in the prion tissue in the brain which can eventually lead to death. These cells accumulate
on the brain, eyes, spinal cord, lymph nodes, tonsils, and spleen of the infected deer.
(Wisconsin Department of Natural Resources 2002) The prions in the muscle tissue in
infected cervids has also tested positive to CWD (Angers et al. 2006). In the later stages
of the disease, the degeneration of the cells causes some alterations observable in cervid
behavior, excessive salvation, loss in appetite, weight loss, loss of body control, and
eventual death. The disease seems to affect twice as many males than females, and the
chances increase of getting the disease with the age. (Grear et al. 2003)
It is the only known TSE to effect elk and deer (Miller & Williams 2002). To date
no animal (elk, white-tailed deer, mule deer) diagnosed with CWD has survived (Miller
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and Williams 2002). Although it’s highly transmissible to other cervids it appears
domesticated animals such as cattle, sheep, and horses have a natural resistance to the
disease and can only contract the disease if it is inserted manually into the brain where
the effects are very similar to the effects in cervids (Miller & Williams 2002). Free-
ranging elk have a much lower prevalence with CWD than mule deer and especially
white-tailed deer (Hlady 2006, Program Manager for CWD in the province of
Saskatchewan, pers. comm.). How the disease is transmitted from animal to animal is still
unknown, but Schauber and Woolf (2003) believe that the disease is transmitted through
bodily fluids via direct and indirect contact. This theory is supported by the excessive
transmission of the disease within the game farm population (high population in a
confined space) and in free ranging cervids (through migratory paths, and grouping
together in the winter months). It explains why the captive populations of animals have
been devastated far more than the free-ranging population.
A study preformed in the Disease Eradication Zone in 2002-2003 by Grear et Al.
(2006) in Wisconsin gave some insight on the incubation period of the disease. The
previous studies have shown the incubation period for CWD was 1.5 years or more
(Miller and Williams 2002), but Grear et al. (2003) results have 5 out of 1021 fawns
tested for CWD tested positive in 2002. Three of the 5 were about 5 months old while
the other two were 9 months and 10 months old respectively. This puts the disease
incubation period to possible birth. There is no known test for CWD while an animal is
alive (Miller and Williams 2002).
3 History of Chronic Wasting Disease
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In 1967, the disease that came to be known as Chronic Wasting disease was first
discovered in a research facility in Northern Colorado in a captive mule deer. It wasn’t
until 1978 the disease was recognized as TSE. In 1981, the first case of CWD in a free-
ranging animal was an elk in Colorado. In 1983, the first-hunter harvest surveillance was
first initiated. The technique is set in which hunters are allowed to kill cervids in a certain
hunting zones coordinated by the government agencies as long the heads of the down
animals are sent in for testing and is the technique currently in use today. In 1985, there
was the first confirmed case of CWD in free-ranging mule deer. In 1990, there was the
first confirmed case of CWD in free-ranging white-tailed deer. In 1996, the first case of
CWD was found in elk in a game farm in Saskatchewan (Chronic Wasting Disease
Alliance 2006).
In 2000/2001, the first diagnostic of CWD in free-ranging mule deer in
Saskatchewan with indications that it may have been transmitted from an elk affect with
CWD from a game farm. In 2001, a diagnostic of an elk imported to Korea from Canada
tested positive for CWD. That same year there is massive depopulation of elk in game
farms in Saskatchewan due to CWD while the USDA declares an animal emergency due
to CWD in elk farms. By 2002, CWD has been found in free-ranging deer populations in
Nebraska, Wisconsin, and in New Mexico. (Chronic Wasting Disease Alliance 2006) In
early 2006, CWD has been found in free-ranging cervids in Alberta along the
Saskatchewan/ Alberta border. (Alberta Sustainable Resource Management 2006)
Figure 1. Locations in North America where CWD has been diagnosed
(Chronic Wasting Disease Alliance 2006)
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4 Current Plans for Chronic Wasting Disease in Canada
In October of 2005, the Government of Saskatchewan published the paper, Canada’s
National Chronic Wasting Disease Control Strategy on behalf of the Inter-Agency
Oversight Committee. According to this paper, Canada has 6 goals in order to control
CWD inside its border:
1. Prevention of further emergencies of CWD in new locations, new prions
emerging, or affecting new species.
This involves the control of importation and exportation of Cervids and
cervid parts interprovincial, intraprovincial, and also the international.
Also includes using updated and effective scientific research.
2. Early detection of CWD in cervid populations.
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Includes creating a national network of CWD and laboratory diagnosis
which will have rapid and complete analysis so it may be distributed to all
participating parties.
3. Planned responses to CWD
Control planning to Contain, Reduce, and eventually Eradicate the disease
in areas where it already exists, while planning in advance for future
occurrences.
4. Effective Management of CWD
Includes scientific research on CWD and various mangament efforts and
appraisal.
Cost, risk, and Feasibility analysis on such plans.
Disease Surveillance programs will need to be evaluated
5. Education and Training
Education of field personnel, scientists
6. Communication
In between all sectors to achieve coordination and a collaboration
5 A Comparative Analysis
The CWD problem in Saskatchewan is somewhat of an isolated event compared to
the situation in Wisconsin, USA. The problem in Wisconsin is in fact a part of the larger
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initial outbreak originally started in Colorado that has spread to surrounding states
including Wyoming, Nebraska, New Mexico, Illinois, and Utah (Grear et. al 2003).
To compare the situation and to get an understanding of the progression of the
disease in Saskatchewan we will compare Saskatchewan’s situation to the situation in
Wisconsin.
5.1 CWD in Saskatchewan
Table 1. Results of Recent CWD Tests in Saskatchewan
(Saskatchewan Environment 2005, Saskatchewan Environment 2006)
Year
White-Tailed Deer
Collected
Mule Deer
Collected Elk
Collected
Total Usable
Samples Negative
Tests Positive
Tests
2000 726 185 89 1000 999 1
2001 2294 1232 340 3866 3865 1
2002 2439 3386 185 6010 6000 10
2003 1876 2784 149 4809 4787 22
2004 1399 5255 0 6654 6620 34
2005 1509 3075 56 3691 3651 35
In 2000, out the 1000 usable cervid samples collected, only 1 sample tested
positive for CWD. In 2001, out of the 3,866 samples collected, again only 1 sample had
tested positive. In 2002, out of the total 6,010 usable cervid samples, 10 tested positive
for CWD. In 2003, out of the total 4,819 usable cervid samples, 22 tested positive for
CWD. In 2004, out of the total 6,654 usable cervid samples, 34 tested positive for CWD.
In 2005, out of the total 3,691 usable cervid samples, 35 tested positive for CWD
(Saskatchewan Environment 2005, Saskatchewan Environment 2006). These samples
were collected from the mandatory sample collection zones. (See figure 2.) One of the
highest concentrations of CWD in white-tailed deer is zone 50, near Nipawin, where the
probability of getting a deer with CWD is 2%. (Hlady 2006, Program Manager of CWD
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in Saskatchewan, pers. comm.) Saskatchewan typically has a larger area with a lower
concentration of cervid populations.
Figure 2. Percentage of CWD in Free-ranging population in Saskatchewan
Based on results retrieved from Saskatchewan Environment
Percentage of CWD in Free-ranging population
0.00000
0.00200
0.00400
0.00600
0.00800
0.01000
2000 2001 2002 2003 2004 2005
Years
Po
pu
lati
on
(%
)
Percentage of
CWD in Free-
ranging
population
5.2 CWD in Wisconsin
Table 2. Results of Recent CWD Tests in Wisconsin
(Wisconsin Department of Natural Resources website 2006)
Year
Total Samples Collected
Total Usable
Samples
Negative Test
Results Positive
Tests
1999-2001 1091 1091 1088 3
2002 40170 40133 39928 205
2003 14901 14901 14784 117
2004 19199 19195 19050 145
2005 24803 24797 24616 181
In the years 1999 to 2001, 1091 usable samples where collected 3 cervids tested
positive for CWD. In 2002, out of the 40,133 total usable samples collected 205 cervids
tested positive for CWD. In 2003, out of the 14,901 total usable samples collected 117
cervids tested positive for CWD. In 2004, 19,195 samples were collected tested and 145
tested positive for CWD. In 2005, 24,797 total testable samples were collected and 181
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cervids tested positive for CWD (Wisconsin Department of Natural Resources 2006). The
landscape in Wisconsin is smaller with a much higher concentration of deer.
Figure 3. Percentage of CWD in Free-ranging population in Wisconsin
Based on results retrieved from Wisconsin Department of Natural Resources
Percentage of CWD in Free-ranging population
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
1999-
2001
2002 2003 2004 2005
Years
Po
pu
lati
on
(%
)
Percentage of CWD in
Free-ranging population
5.3 Analysis
We have two very different situations in these two places. In Wisconsin we have a
high density area, with an equally high population. The results of the CWD hunter-
harvest surveillance in Wisconsin were 3 to 4 times larger than the results of CWD
hunter-harvest surveillance in Saskatchewan. Samples are required from zones 5, 8 to 14,
19, 23 to 26, 43, 45 to 47, 50, 53, 62, 63, 67 , 68 while there are positive test results from
Zones( and thusly Herd Reductions Areas): 12, 13, 14, 46, 47, 50.
For the year 2005, Wisconsin had 24,797 usable samples with 181 positive tests. In
the same year for Saskatchewan, there were 3,691 testable samples with 35 positive tests.
So in 2005, the average percentage of getting an animal with CWD is 0.7% in Wisconsin,
while the average percentage of getting an animal with CWD in Saskatchewan is 0.9%
(varies with location). These results are very troubling due to the current rate of CWD in
Saskatchewan and Wisconsin seems to be spreading. (See Figures 3 & 5)
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6 CWD in Alberta
Models of CWD epidemic dynamics suggest an early aggressive intervention via selected
culling and an increase of generalized population reduction has shown the best possible
results of preventing the establishment of CWD (Miller and Williams 2002). Alberta’s
strategy has taken this fact and has applied it to its policies creating an aggressive CWD
border plan. (Alberta’s Sustainable Resource Management 2006) Along the
Saskatchewan and Alberta border there are three confirmed outbreaks of CWD. (See
Figures 2 and 6) Currently there are three Herd Reduction Areas in Alberta in hunting
zones; 150, 151, 234. Then there are compulsory Head submission zones (zones 150,
151, 234, 256, 500) and the voluntary head submission zones in Alberta (zones 152, 144,
148, 162, 200, 202, 203, 232, 238, and 236) Alberta recently opened the Herd Reduction
Areas this January to March and in that time they collected and tested 1688 deer (1475
mule deer, 213 white-tailed deer), 9 tested positive for CWD (Alberta’s Sustainable
Resource Development 2006).
Figure 4. CWD Herd Reductions Areas and the Voluntary Deer Head Submission zones
(Alberta’s Sustainable Resource Development 2006)
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7 What can Hunters do to Help fight Chronic Wasting Disease
Through various government agencies in the Provinces and States that have been
affected by CWD, their main weapon against the disease has been the hunter-harvest
surveillance. This depends solely upon the hunters, who can participate by going to
various government instillations and getting Herd Reduction tags/ CWD control tags
(Alberta, Saskatchewan, Wisconsin, etc.) or Disease Eradication tags (Wisconsin, and
other American states), as long any and all cervids that are killed in those areas have their
heads sent in for testing. Most of these agencies are in accordance in how people should
handle the downed animals. Avoid handling the areas where CWD usually accumulates
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such as; the brain, lymph nodes, eyes, spinal cord, tonsils, and spleen. (Wisconsin
Department of Natural Resources 2002)
These agencies do not accept animals with antlers so care must be taken when
removing the antlers from the skull. If any brain tissue is exposed put a paper towel over
it and don’t handle it as it is required for testing. (Saskatchewan Environment 2005) The
various agencies (Alberta’s Sustainable Resource Development, Saskatchewan
Environment, etc.) require some additional information about such as the time, date,
hunting zone you were killed the animals, and the GPS co-ordinates of where the animal
was killed. (Saskatchewan Environment 2005) All these agencies advise wearing latex
gloves when handling the dead animal, and advise against eating the meat of an animal
being sent for testing until the results are posted on the government agencies
website.(Wisconsin Department of Natural Resources 2002, Saskatchewan Environment
2005) A recent of study of CWD in cervids show that infected cervids may have infected
prions in their muscle tissue and may be transmissible to humans in this form. (Angers et
al. 2006)
Hunter/harvest surveillance is essential to the tracking and studying of CWD. It gives
us usable samples for examination of the disease and guides to see if the disease is
spreading and if our efforts are effective. Currently in Saskatchewan there are indications
that the disease is still spreading. (Hlady 2006, Program manager of CWD in
Saskatchewan, pers. comm.) But with the help of the hunter harvest surveillance and the
coordination of government agencies and independent researchers come new studies and
new technologies in the hopes of containing and eventually eliminating the disease.
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8 Literature Citied
Alberta’s Sustainable Resource Development. 2006. Chronic Wasting Disease Alberta-
Saskatchewan 2006 Border Program Overview. Alberta’s Sustainable Resource
Development, Edmonton, Alberta. Retrieved 15 October 2006 from
http://www.srd.gov.ab.ca/fw/pdf/2006_AB_Sask_border_prg.pdf.
Angers R.C., Browning S.R., Seward T.S., Sigurdson C.J., Miller M.W., Hoover E.A.,
Telling G.C. 2006. Prions in Skeletal muscles of Deer with chronic wasting
disease. Science 311 (5768):1117. Retrieved 2 November 2006, from
Chronic Wasting Disease Alliance. 2006. Chronic Wasting Disease. Pyron Technologies,
Inc., N/A. Retrieved 4 October 2006 from http://www.cwd-
info.org/index.php/fuseaction/about.map.
Grear DA, Samuel MD, Langenberg JA, Delwyn K. 2006. Demographic patterns and
harvest vulnerable of chronic wasting disease infected white-tailed deer in
Wisconsin. Journal of Wildlife Management 70(2):546-553
Miller MW, Williams ES. 2002. Chronic Wasting Disease in deer and elk in North
America. Revue scientifique et technique (International Office of Epizootics)
21(2): 306-316. Retrieved 4 October 2006 from National Center for
Biotechnology Information database.
Mothwing camo technologies. 2006. Mothwing Camo Technologies Camouflage Patterns
and Products. Mothwing Camo Technologies, Helenwood, Tennessee. Retrieved
27 October 2006 from http://www.mothwingcamo.com/images/White-tailed-
Deer-L.jpg
Saskatchewan Environment. 2005. Canada’s National Chronic Wasting Disease Control
Strategy. Saskatchewan Environment, Regina, Saskatchewan. Retrieved 16
October 2006 from http://www.se.gov.sk.ca/fishwild/NCWDCS2005.pdf.
Saskatchewan Environment. 2006. Provincial Summary of CWD Test Results.
Saskatchewan Environment, Regina, Saskatchewan. Retrieved 4 October 2006
from http://wildlife1.usask.ca/cwd/provincial_summary.php.
Saskatchewan Environment. 2006. Chronic Wasting Disease 2006 Management Program.
Saskatchewan Environment, Regina, Saskatchewan. Retrieved 4 October 2006
from
http://www.se.gov.sk.ca/fishwild/Chronic%20Wasting%20Disease%202006%20
Management%20Program.pdf.
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Saskatchewan Environment. 2005. Chronic Wasting Disease Management Program Fall
2005. Saskatchewan Environment, Regina, Saskatchewan. Retrieved 4 October
2006 from http://www.se.gov.sk.ca/fishwild.
Schauber EM, Woolf A. 2003. Chronic Wasting Disease in elk and deer: a critique of
current models and their application. Wildlife Society Bulletin 31(3):610-616.
Pybus MJ. 2006. Alberta’s Chronic Wasting Disease Management Programs in 2006 and
upcoming surveillance. Alberta’s Sustainable Resource Development, Edmonton,
Alberta. Retrieved October 22 2006 from
http://www.srd.gov.ab.ca/fw/diseases/CWD/pdf/2006%20CWD%20report%20an
d%20upcoming%20surveillance.pdf
Veterinary Services. 2002. Chronic Wasting Disease. Animal & Plant Health Inspection
Service, United States Department of Argiculture. Retrieved 15 October 2006
from http://www.aphis.usda.gov/lpa/pubs/fsheet_faq_notice/fs_ahcwd.html
Wisconsin Department of Natural Resources . 2002. Understanding Chronic Wasting
Disease in Wisconsin. Wisconsin Department of Natural Resources, Madison,
Wisconsin. Retrieved 23 October 2006 from
http://www.dnr.state.wi.us/org/land/wildlife/whealth/issues/CWD/doc/cwdbook
.pdf.
Wisconsin Department of Natural Resources . 2006.2006 CWD Zones Special
Regulations. Wisconsin Department of Natural Resources, Madison, Wisconsin.
Retrieved 23 October 2006 from
http://www.dnr.state.wi.us/org/land/wildlife/whealth/issues/CWD/doc/cwdbook
.pdf.
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Secondary Citation
Miller MW, Thorne ET, Williams ES. 2002. Chronic Wasting Disease: Implications and
Challenges for Wildlife Management Presented at the 67th North American
Wildlife and Natural Resource Conference. S Williams, technical coordinator.
Proceedings of special session 1 on Wildlife Diseases: Crying Wolf or Crying
Shame?. N/A
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Personal Communication
Hlady M. 2006. Personal interview, 3 November. Program manager of CWD for the
province of Saskatchewan, Regina, Saskatchewan.
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9 Appendix A. Herd Reduction Areas and Zones required to deposit samples in Saskatchewan
Based upon results from Saskatchewan Environment
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10 Appendix B. Herd Reduction Zones and Disease Eradication Zones for 2006 in Wisconsin
(Wisconsin Department of Natural Resources 2006)