South Dakota, the source of the nation's first diagnosed case of chronic wasting disease (CWD) in a domestic elk herd, has been declared CWD-free.
The announcement, made by Sam Holland, state veterinarian, is a result of elk and deer in South Dakota reaching the 36-month mark of being CWD-negative, the generally accepted CWD incubation period. Since CWD was first discovered in 1997, all quarantined herds have been eliminated or depopulated and no new cases have been detected. A final shipment of a small group was recently sent to the National Veterinary Services Laboratory, in Ames, IA, for ongoing research.
South Dakota was the first state to enact a comprehensive CWD control program, and it has proven successful. "Our experience demonstrates that with a good, solid, mandatory program, this disease can be eliminated," Dr. Holland said. "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 success in South Dakota is precedent setting. "We feel even more confident that CWD can be controlled and eliminated, thanks to the efforts of those in South Dakota and elsewhere in North American Elk Breeders Association (NAEBA). "Just like tuberculosis in farmed elk, which we licked in less than six years, we also will be successful in eliminating CWD."
South Dakota elk breeders have taken a successful, proactive approach to controlling and eliminating CWD in farmed herds. When CWD was discovered in 1997, South Dakota elk breeders unanimously voted to support emergency legislation to aggressively address CWD and worked with Dr. Holland in developing and implementing a state-regulated surveillance and monitoring program to detect and eliminate the disease. In addition, ranchers of infected herds, out of respect for consumers' concerns, did not sell antler from there herds and voluntarily eradicated their herds. In February, 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.
"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," Holland said.
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.
CWD, a rare disease, is a transmissible spongiform encephalopathy (TSE) of elk and deer species. The first case of CWD, in a private herd in the United States, was identified in a 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 a 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 also has been discovered in the wild in the extreme west of Nebraska.
NAEBA has taken a leading role in CWD eradication and has developed a model CWD eradication program that has been implemented by many states and which has shaped the U.S. Department of Agriculture program scheduled for implementation in October, 2001. The Canadian Food Inspection Agency (CFIA) developed a similar program that became effective in October, 2000.
For more information, contact the North American Elk Breeders Association, Platte City, MO, (816) 431-3605.