CHRONIC
WASTING DISEASE

Alberta's response program

A summary of activities from January to March 2006

    Chronic wasting disease (CWD) is a chronic degenerative and ultimately fatal disease of cervids (deer, elk, and to a lesser extent moose). CWD has the potential to significantly reduce cervid population densities and is considered a threat to deer populations in Alberta. Through CWD surveillance and management activities previous to 2006, two geographical areas were identified as potentially high risk for CWD incursion into Alberta: the Dilberry Lake Provincial Park area south of Chauvin (WMU 234), and the region around the confluence of the Red Deer and South Saskatchewan Rivers (WMUs 150 and 151). At the end of 2005, four CWD-positive mule deer had been identified in Alberta, all from the latter region 
(see map at: http://www.srd.gov.ab.ca/fw/diseases/CW D/pdf/CWD_survellance.pdf ). An International Expert Panel, convened in 2004 to examine the epidemiology and risks of CWD to cervids, concluded that CWD is likely not native to cervid populations in Canada and that there are no natural barriers to further spread of the disease in affected areas. In light of these findings, and the potential for CWD to negatively affect cervid populations, the Fish and Wildlife Division of Alberta Sustainable Resources Development made it a priority to prevent or limit the spread of CWD into the province. 

     Toward this objective, the Fish and Wildlife Division implemented a CWD response program from mid-January to mid-March 2006. The specific goals of the program were to limit disease transmission by reducing deer densities in the vicinity of CWD-positive deer, and to determine the extent of the disease distribution by conducting surveillance upstream on each of the South Saskatchewan and Red Deer rivers. 

     Intensive herd reduction was conducted in three areas, all within approximately 10 km of previous cases of CWD in wild deer in Alberta or Saskatchewan: Red Deer River (RDR), South Saskatchewan River (SSR), and Dilberry Lake Provincial Park (DLPP). In herd reduction areas, staff were instructed to shoot any deer that could be safely shot and recovered, regardless of species, sex or age. During the Dilberry Lake delivery, a deer density of 1 km2 (recommended by the International Expert Panel as a threshold for limiting CWD transmission) was reached after two days of herd reduction, so the program was closed down. Aerial surveys were conducted before and after each delivery to determine deer distributions and the changes in deer numbers. 

     Enhanced surveillance for CWD was conducted upstream from the RDR and SSR herd reduction areas (west to Highway 886 in the former, and west to CFB-Suffield in the latter). The goal was to collect and test 250 samples of adult deer from each of these areas. 

     The field response program relied on Fish and Wildlife staff to shoot deer, collect heads for CWD testing, collect reproductive samples, salvage hides and salvage usable meat. In addition, incisor bars were collected for aging purposes and tissues samples for genetic analyses. Staff from Saskatchewan Environment participated in disease control activities within the Saskatchewan portions of the 10km circles. All deer were processed in Oyen by Fish and Wildlife Division staff. Most of the heads were tested by Alberta Agriculture, Food and Rural Development in Edmonton, while a few were tested by Prairie Diagnostics in Saskatoon. 

     Hides were provided to the Oyen Rod and Gun Club for fundraising programs. Antlers were provided to the provincial hunter education programs for teaching purposes. Salvaged meat from CWD-negative deer was distributed through normal Fish and Wildlife Division channels. Guiding principles for the program were safety of staff and the public in conjunction with effective and efficient shooting of deer with minimal disturbance to landholders and local residents. 

     In total, 1,688 deer (1,475 mule deer, 213 white-tailed deer) were collected between January 23 and March 11, 2006. Collection activities in the herd reduction areas yielded 1,022 deer from the RDR / SSR areas (884 MD and 138 WTD) and 40 from the Dilberry area (27 MD and 13 WTD). Collections during the enhanced surveillance programs yielded 361 deer from the upstream Red Deer River area (319 MD and 42 WTD) and 265 deer from the South Saskatchewan River area (245 MD and 20 WTD). With the exception of one serious vehicle accident, all safety, surveillance and initial herd reduction goals were achieved successfully. In total, nine CWD-positive deer were collected in Alberta and two in Saskatchewan. Assuming the RDR and SSR herd reduction areas can be treated as a population unit, estimated CWD prevalence in deer in this area is 1.1 per cent (95 per cent confidence limits 0.5-1.9 per cent). By species, estimated prevalence is 1.3 per cent in mule deer (95 per cent confidence limits 0.6-2.2 per cent). No positive white-tailed deer were detected; however, sample size was relatively small. 

     Public meetings were held in Empress and Chauvin prior to and after disease control activities to provide information about CWD, its management and control options, an overview of the response programs, data on local deer populations and to gain input for future deer harvest options. Meetings were held with the Chauvin CWD Public Advisory Committee and with local landowners in the Empress area. In addition, Fish and Wildlife Division staff made presentations at the Alberta Fish and Game Association Annual Meeting, Brooks Fish and Game Association chapter meeting, Wilderness Sportsmen’s Club chapter meeting, Alberta Professional Outfitters Society Executive meeting, Alberta Chapter of The Wildlife Society Annual Meeting and the Alberta Agriculture lunch-time seminar series. Also, Fish and Wildlife staff were invited by Saskatchewan Environment to present an overview of the CWD winter program at a public meeting in Leader, Saskatchewan. In all venues, the audience was encouraged to ask questions and provide comments and suggestions. 

     Total direct costs of the winter CWD program were in the $470,000 range. Primary costs were associated with staff expenses, overtime as well as field equipment and supplies. Diagnostic costs were provided in-kind by Alberta Agriculture, Food and Rural Development. 

     This program could not have been completed without the significant efforts of Fish and Wildlife Division staff, particularly staff from Enforcement-Field Services and Wildlife Management Branches. The field program directly involved over 99 permanent and wage staff, including officers, biologists, technicians and administrative staff who contributed over 14,000 hours to the program. 

     We also acknowledge the support and assistance of local residents, landowners, and landholders. This program would have ground to a halt without their patience and support.

M.J. Pybus is the Provincial Wildlife Disease Specialist for the 
Fish and Wildlife Division in Edmonton.