wasting disease (CWD) is only known to affect members of the deer
family, including mule deer, white-tailed deer, wapiti (elk), and moose.
The origins of the disease are currently unknown. Although identified in
the 1970ís, CWD probably occurred in a localized area of Colorado/
Wyoming/ Nebraska for quite some time. It may be the result of local
mutation of a similar agent that causes scrapie in domestic sheep. There
is also the possibility that CWD has always been present in wild deer
populations at very low levels, but the majority of biologists working
on the disease do not support this idea.
is a prion disease associated with protein changes in the brain. Damage
to the brain results in changes to behaviour, attitude, and metabolism.
Some of these changes include excessive salivation, lethargy, incoordination, and drooping head and ears. Individuals cannot maintain
weight and slowly waste away. There is no known cure or treatment for
CWD, and all infected individuals eventually die.
the short term, mortality due to CWD does not seem to affect overall
productivity in infected populations. However, theoretical models
suggest that mule deer populations in Colorado, at the heart of the
affected area, will decline in 40-100 years and eventually die out. Thus
the disease has the potential for large ecological and economic impacts.
exact mode of transmission is still unknown, but the disease can be
transmitted between individuals both directly via contact with an
infected individual and indirectly via exposure to soils contaminated
with the infectious prions. Infectious material survives in the
environment for an unknown period. Management therefore focuses on the
rapid elimination of new outbreaks and the prevention of spread from
existing disease areas.
more information on chronic wasting disease, please visit one of the
Sustainable Resource Development
(search for CWD)
Canada Cooperative Wildlife
Canadian Food Inspection