Chronic Wasting Disease (CWD) surveillance update December 10, 2020

Fall hunting seasons are pretty well finished but CWD surveillance has much more work to do. We have many many more heads to test, but to date we have tested over 2,500 heads from the 2020 seasons and detected CWD in 234. The disease continues to occur primarily in mule deer bucks (127 of the 234 cases from 2020). The number of positive white-tails seems to be increasing but further analyses will have to wait until all the results are in.

We detected CWD in 4 wildlife management units (WMUs) not previously known to have infected deer. One case in particular, near Chain Lakes in WMU 304, is startlingly close to the southern foothills. Other ‘new’ units WMU 210, 214 and 220 reaffirm the steady westward expansion of CWD.

The 49 CWD drop-off freezers are being removed the 2nd and 3rd weeks of December. All will be gone by December 17. Testing labs will be closed in the 4th week of December and open again on January 4, 2021.

Note that the head drop-off freezers are ONLY available from mid-October to mid-December. Deer heads can also be dropped off at Fish and Wildlife offices throughout the year during office hours. However, there may be COVID-19 limitations and hunters are encouraged to call an office to determine local head submission options. See page 13 of the 2020 Alberta Guide to Hunting Regulations for office locations and phone numbers. For further information, see: Chronic Wasting Disease – Information for Hunters.

Regardless of test results, hunters are sent an email using the email address in their AlbertaRELM account. Hunters without an email address in their account are phoned only if the animal is positive for CWD.

The total number of CWD cases detected in wild deer in Alberta since September 2005 is 2,982.

Free CWD replacement licences no longer available

The original intent in offering replacement licences was to encourage hunters to return to areas of Alberta where CWD was first detected. However, hunter interest and harvest in the CWD area remains high and free replacement licences are no longer considered necessary.

Initially, very few harvested deer had CWD and thus very few replacement licences were offered. However, with increased prevalence and distribution of CWD, this is no longer the case.

Increasing numbers of hunters with a CWD replacement licence are creating a disproportionate harvest opportunity and advantage over those hunters who must build priority points to access a licence, particularly for antlered mule deer.

CWD occurs in pockets of localized deer, so hunters harvesting from the same small population each year are more likely to harvest an infected deer and gain access to annual free replacement licences. As the number of CWD cases increases over time, the number of replacement licences becomes disproportionate to the number of licences available to individuals who apply for draws, and limits the diversity of opportunity for broader populations of hunters who wish to have that opportunity.

CWD and human health

While there are no known cases of CWD in humans, health authorities recommend precautions. Additional information is available at: CWD and Public Health.

Thank you to hunters, guides and landowners

It is hard to believe we have been tracking this disease in wild deer in Alberta for over 20 years. Alberta began CWD hunter surveillance in 1998 and has one of the best continuous datasets documenting the occurrence and patterns of CWD in wild cervids, specifically in prairie / parkland ecosystems. The continued support of hunters, guides and landowners is the basis for the strength of our surveillance data.

The success of the CWD surveillance program relies heavily on participation by hunters, guides, and landowners to ensure a successful harvest that provides heads to be tested. We heartily acknowledge and thank all those who helped make the program so successful and look forward to your continued support.

Attention Hunters!

In order to track chronic wasting disease in our deer populations, submission of deer heads for CWD testing is mandatory in specified WMUs in eastern Alberta. Submit deer heads for CWD testing during rifle seasons at any of the 24-hour freezers in Edmonton, Calgary, and across eastern Alberta.

Note that the deer head drop-off freezers are only available from mid-October to mid-December. However, CWD surveillance in Alberta is a year-round program and suitable deer heads can be submitted for testing at a Fish and Wildlife office throughout the year during office hours. See page 13 of the 2020 Alberta Guide to Hunting Regulations for office locations and phone numbers. The guide can be found at: Alberta Regulations.

Please also note that for biosafety and logistical reasons, we are unable to return heads to a hunter. If you wish to keep any part of the head or antlers, you should remove it before submitting the remaining portion for CWD testing. Additional information about preparing and submitting heads can be found at: Chronic Wasting Disease – Information for Hunters.

Note that hunters receive negative test results directly at the email address associated with their individual AlbertaRELM account. The email process is the only notification hunters receive when their animal is negative for CWD.

Starting in 2019: Hunters who harvest a CWD positive deer will be sent an email, as above. Hunters without email contact in their AlbertaRELM account will be notified by phone.

Patterns of CWD in Alberta

There are significant overall patterns of disease occurrence in Alberta. CWD continues to occur primarily in mule deer in comparison to white-tailed deer despite testing large numbers of both species. Similarly males are more likely to be infected than females.

Overall CWD prevelance 1996-2019
Annual CWD prevelance 2010-2019

Analyses of previous data determined the weighted CWD occurrence in Alberta is:

  • Mule Deer: male 1.00 female 0.4
  • White-tailed Deer: male 0.3 female 0.1

Thus male mule deer are the most likely, and female white-tailed deer the least likely to be infected with CWD.

The geographic distribution of CWD is clustered in some WMUs but continues to expand westward.

In conjunction with the University of Alberta, we used Alberta’s surveillance data to model the risk of CWD in male mule deer.

We looked at three periods:

  • a seven-year period since the first case (2005-2012)
  • more recent data (2013-2017)
  • the cumulative risk over all years showing the progressive increase of risk from 2005 to 2017

View the CWD risk report at: Chronic wasting disease change in risk over time in male mule deer – 2005 to 2017.

The following map tracks the year where CWD was first detected in select Wildlife Management Units (WMUs): Chronic wasting disease in Alberta by year of first detection.

The prevalence (% infected) of CWD in male mule deer continues to increase in Alberta. For details, see: Prevalence (% infected) of CWD in male mule deer – 2010 and 2019.

The finding of CWD in a moose near the South Saskatchewan River valley in 2012 is the first such case identified in Canada: CWD in Moose in Alberta.

Specific information about the CWD hunter surveillance program is provided at: Chronic Wasting Disease – Information for Hunters

The CWD Freezer Locations currently posted on the Information for Hunters page has all the correct information for 2020.

  • CWD surveillance is focused on the Alberta/Saskatchewan border; however, hunter-killed deer (and elk) are accepted from anywhere in the province (as in all previous years)

2019 Final fall CWD surveillance results

In 2019 we tested 10,400 heads:

  • CWD was detected in 1160 animals (11.2% overall: 986 mule deer (769 males, 217 females), 169 white-tail (155 males, 14 females), 3 elk (2 male, 1 female), and 2 moose (1 male, 1 female):
    • 17.5% of 5,632 mule deer
    • 3.9% of 4,295 white-tailed deer
    • 1.3% of 231 elk (primarily from CFB Suffield)
    • 0.9% of 232 moose (primarily from CFB Wainwright)
  • In the 9,877 deer for which gender/sex was reported, CWD was detected in:
    • 24.5% of 3,133 male mule deer
    • 8.8% of 2,485 female mule deer
    • 4.8% of 3,226 male whitetails
    • 1.4% of 1,033 female whitetails
  • Patterns in the data in 2019:
    • In many cases in eastern Alberta, the gender- and species-specific prevalence is much higher in individual Wildlife Management Units (WMUs).
    • CWD was detected in 10 WMUs where CWD was not previously known to occur, bringing the total to 53 WMUs with at least one documented CWD case.

To learn more about CWD Surveillance in Alberta, see: CWD Surveillance and Response.

For past CWD surveillance results and a general timeline of CWD in Alberta, see: CWD History in Alberta.

CWD map and statistics

  • Map: Chronic Wasting Disease in wild cervids in Alberta

    This record in the Open Publications Portal Includes:

    • Chronic Wasting Disease in wild cervids in Alberta (2019)
    • Chronic Wasting Disease in wild cervids in Alberta (2005 to 2018)
    • Chronic Wasting Disease in wild cervids in Alberta (2005 to 2017)
  • Statistics: Chronic Wasting Disease in wild cervids in Alberta

    This record in the Open Publications Portal includes:

    • Chronic Wasting Disease in wild cervids in Alberta (2018)
    • Chronic Wasting Disease in wild cervids in Alberta (2017)
    • Chronic Wasting Disease in wild deer and a moose in Alberta (2011-2016)
    • Chronic Wasting Disease in wild deer in Alberta (2005 to 2010)

News releases and information bulletins