Renewed testing for chronic wasting disease (CWD) in 2007 turned up no evidence of the disease, but the Missouri Department of Conservation says it will continue stepped-up monitoring for two more years.
CWD is a degenerative neurological malady that affects the deer family but has not been found to afflict any other animals.
It was first documented in Colorado in 1967.
It has since spread to other states. Missouri began testing for the disease in 2002, after an outbreak in Wisconsin. CWD has never been documented in the Show-Me State.
Prior to the Wisconsin outbreak, Missouri had tested only sick deer for CWD.
In 2002, the Conservation Department continued this "targeted" testing and added a comprehensive testing program.
Between 2002 and 2004 the agency tested more than 20,000 deer, using a random sample of hunter-killed deer from every county in the state.
The tests showed no cases of CWD.
"We were very reassured by those results," said Resource Scientist Lonnie Hansen, who handles the Conservation Department's deer-management program. "Following the intensive, three-year sampling effort, we went back to targeted testing. We decided to conduct another round of comprehensive monitoring as part of a prudent surveillance program. We want to be certain that if CWD does reach Missouri we know about it early enough to take the necessary control measures."
For the current round of comprehensive CWD monitoring, the Conservation Department divided the state into three zones -- northern, central and southern.
It collected samples from hunter-killed deer in the northern zone first, testing approximately 200 deer from each of several five-county sampling areas within the zone. Again, results all came up negative.
The Conservation Department will test deer from the central zone this year and from the southern zone in 2009.
One difference from past testing is how the Conservation Department is obtaining samples.
In the first round of comprehensive testing, the agency took tissue samples from deer brought to check stations.
This time it is working with taxidermists to obtain the necessary samples.
Twenty-one taxidermists participated in the first round of testing, gathering 1,221 samples.
Targeted testing of sick deer continues.
"Last year's testing does not guarantee that Missouri's deer herd is CWD-free," said Hansen, "but statistically speaking it gives us a high degree of confidence that the disease is not present in a particular area."
For more information about CWD, visit mdc.mo.gov/hunt/deer/cwd/.