Chronic Wasting Disease – Surveillance and response

Overview

Chronic Wasting Disease (CWD) is a fatal disease in the brain of wild and farmed cervids (elk, mule deer, white-tailed deer and moose).

Alberta began CWD surveillance programs in the farmed and wild cervid populations in 1996. The programs for wild cervids are delivered by Alberta Environment and Protected Areas; Alberta Agriculture and Irrigation delivers the surveillance of farmed deer and elk.

Surveillance of wild cervids

Alberta’s surveillance program assesses the presence or absence of CWD in free-ranging deer, elk and moose, but focuses primarily on mule deer and white-tailed deer.

The division works co-operatively with hunters, guides and local residents to achieve objectives such as:

• collecting and analyzing heads of wild deer for evidence of CWD
• providing surveillance data necessary to assess the geographic distribution of CWD in wild populations
• co-ordinating with similar programs for farmed elk and deer

The surveillance program for wild cervids is based largely on submission of deer heads by hunters. In designated parts of the province, submission of deer heads may be mandatory or voluntary.

Hunter-harvested deer heads may be supplemented with additional samples collected by provincial staff during disease control or routine field activities. This program targets individual emaciated or neurologic (strangely acting):

• antelope (pronghorn)
• caribou
• deer
• elk
• moose

Surveillance target areas

The wildlife surveillance program focuses on identified CWD risk areas, primarily:

• along the Alberta-Saskatchewan border
• along the leading edge of the enzootic (established) area of CWD in wild deer
• around confirmed cases of CWD in wild or farmed cervids in Alberta outside the enzootic area

Random targeted areas elsewhere in the province may be chosen for increased surveillance effort.

Communicating with hunters

The Alberta government has a communications program to inform hunters of the value in submitting the head of deer they harvest. Messages may reach hunters through:

• websites and social media
• materials sent to outdoor magazines, newspaper and radio outlets, hunting-licence vendors and hunting organizations
• direct contact with Fish and Wildlife staff
• notices sent to draw-licence recipients

Testing for CWD

Laboratory tests involve microscopic and immunologic examination of a specific site in the animal’s lymph nodes and/or brainstem. The Alberta tests meet international standards for CWD diagnosis.

Lab tests on wild cervids are conducted by the Ministry of Agriculture and Irrigation. Results are reported to the government’s Fish and Wildlife Stewardship on an ongoing basis. Summary results are available at Chronic Wasting Disease Updates.

All hunters who submit deer heads for CWD surveillance will be informed of test results on their deer. A list of positive cases is available on the Chronic Wasting Disease Updates page.

Response to positive cases

When CWD is found in the wild or if there is apparent increased risk, 3 primary tools may be applied:

• increased recreational harvest opportunities
• herd reduction programs
• increased public information and education

All programs are updated or revised based on field information and new research data.

Surveillance of farmed cervids

Alberta Agriculture and Irrigation works closely with the farmed-cervid industry on surveillance programs. This includes mandatory examination of the heads of animals that die for any reason, including slaughter. The animals must be at least 1 year old.

Meat from slaughter animals is held until there are negative test results from the lab. Those results are forwarded to the slaughter plant.

Before any captive elk or deer can be imported into Alberta, there is stringent assessment of all disease risks, including CWD.

For more information and testing results regarding CWD in farmed cervids, visit Mandatory Chronic Wasting Disease Surveillance Program.

Reportable disease

CWD became a federal reportable disease in 2001. The Canadian Food Inspection Agency (CFIA) has a national program of CWD surveillance and control in farmed cervids at CWD Voluntary Herd Certification Programs.