CHRONIC WASTING DISEASE
Chronic wasting disease (CWD) is a disease of the brain of deer, elk and moose which is similar to BSE (mad cow disease) in cattle and scrapie in sheep. It was introduced into farmed elk in Saskatchewan from infected elk imported from the US in the late 1980s, and has since spread to wild white-tailed deer, mule deer and elk populations in several locations within Saskatchewan and Alberta. The disease is caused by infectious proteins, called prions, which can be transmitted by animal-to-animal contact or by contact with environments contaminated with these infectious agents. Infected animals become weak and emaciated and tend to drink large amounts of water and salivate excessively. CWD is invariably fatal and could have severe impacts of deer populations throughout North America. It appears unlikely the disease can be transmitted to humans and most domestic animals but the full host range of CWD is unknown.
WHAT WE ARE DOING
Beginning in 1997, the Saskatchewan Ministry of Environment (MOE) and the CWHC started a CWD surveillance program for wild deer, elk and moose. This surveillance program was based primarily on the testing of hunter-killed animals and to a lesser extent on the testing of sick or dead cervids. The program ended in 2012 with over 45 000 heads tested and a total of 387 positives from 20 Wildlife Management Zones (WMZs) (see map). The CWHC continues to test cervids that are submitted through our diagnostic program and we have continued to diagnose CWD in new areas.
Starting in 2006 the CWHC embarked on a research program in Saskatchewan with the aid of PrioNet and the MOE to look at factors affecting the spread of CWD. Phase I of the project focused on direct and indirect contact rates, habitat selection, long distance movements and survival trends as they relate to CWD. Phase II which began in 2009 focused on direct observations of mule deer and their use of environmental sites to determine risk of infection by CWD.