South Dakota Herds Free of CWD
March 13, 2001, Platte City, MO-State Veterinarian Sam Holland announced on March 5 that South Dakota is free of chronic wasting disease (CWD). CWD is a transmissible spongiform encephalopathy (TSE) of elk and deer species. The first case of CWD in the United States was identified in a private South Dakota herd in 1997. It is thought that most of the CWD-infected domestic herds in the United States and Canada can be traced to this herd, which traces to the Colorado Division of Wildlife research facilities.
CWD was first identified in mule deer in 1967 at the Colorado research facility. Animals from this facility were given to the Denver Zoo. The Denver Zoo gave some mule deer to the Toronto Zoo and also sold some animals that eventually arrived at an elk ranch in South Dakota.
CWD has been found in some herds of farmed elk in four other states and in the province of Saskatchewan. It is present in the wild in northeastern Colorado and southeastern Wyoming in the areas where the disease first appeared in the wildlife research facilities. An infected mule deer has also been detected in the wild in the extreme west of Nebraska.
When CWD was discovered in South Dakota, the farmed elk industry quickly endorsed Dr. Holland's plan to begin a state-regulated surveillance and monitoring program to detect and eliminate the disease. In February of 1998, the state legislature approved the program that includes mandatory testing of all elk that die or are harvested, along with stringent movement and import regulations that prohibit such movements until documented surveillance proves no evidence of the disease.
All potentially exposed herds were placed under quarantine, including any with evidence of exposure during the five years prior to implementation of the program. All affected herds have now been completely eliminated with the final shipment of a small group for ongoing research at the National Veterinary Services Laboratory in Ames, Iowa.
South Dakota was the first state to enact such a control program, and it has proven successful. Dr. Holland said, "Our experience demonstrates that with a good, solid, mandatory program, this disease can be eliminated. We now have over three years of records to certify that the elk population has been very closely monitored with no further evidence of disease."
"The elk industry in this state operates under the most stringent health regulations in the country and has demonstrated freedom from tuberculosis, brucellosis, bluetongue, anaplasmosis, and now-CWD," states Holland.
No evidence of CWD has appeared in the state's wildlife after three years of targeted surveillance of free-ranging elk and deer by the Department of Game, Fish and Parks, in cooperation with the South Dakota Animal Industry Board.