Chronic Wasting Disease in Minnesota
Chronic Wasting Disease (CWD) is a contagious and fatal neurological disease of deer and elk. CWD affects both captive and free-ranging cervids in North America. Currently there is no effective treatment for CWD and management practices to prevent CWD transmission in both captive and wild cervids are limited.
With funding provided by the Minnesota Rapid Agricultural Response Fund, a team led by Dr. Scott Wells conducted a study to evaluate the known transmission pathways for CWD in Minnesota farmed cervids.
CWD and Cervid Facts
- Naturally occurring CWD is known to occur only in animals born in the United States and Canada
- CWD has been found in free-ranging cervids in 18 states
- 13 states have experienced CWD in farmed cervids, including 5 herds in Minnesota as of 2012
- Minnesota is fifth in the nation for the number of commercial white-tailed deer farms and sixth nationally in the number of farmed deer (2007 USDA Agricultural Census)
- Minnesota requires registration of all farmed cervids, and as of January 2013, there were 517 farmed cervid herds registered with the Minnesota Board of Animal Health
- To protect the farmed cervid industry, Minnesota created a voluntary CWD testing program in 1996
- In 2013, testing requirements in Minnesota were changed to require mandatory surveillance testing in all deaths of cervids 12 months or older, which aligns with United States Department of Agriculture’s Animal Plant Health and Inspection Services Program Standards for CWD
- Several species of cervids are susceptible to CWD through multiple exposure routes including: oral, aerosol, intravenous, and environmental exposures
- CWD infection can be transmitted through various inoculum types, such as brain, blood, and saliva
- The source of infection in initial CWD-infected farmed cervid herds in Minnesota appeared to be related to introductions of cervids from other farms
- The most recent CWD-infected farmed cervid herd in Minnesota did not appear to be related to introduction of infected cervids, as this herd had been closed to new introductions for over 10 years
- CWD is a threat to the farmed cervid industry in the United States
- Existing biosecurity practices do not appear to provide complete protection against introduction to farmed cervid herds, and federal funding is no longer available for control programs (including indemnification after depopulation of detected herds)
- Additional research is needed to identify new disease management options for CWD in farmed cervids
Drs. Cara Cherry and Joao Ribeiro-Lima, College of Veterinary Medicine, University of Minnesota are additional contributors to this research.