MDC reports 162 new cases of CWD for 2023 surveillance year

JEFFERSON CITY, Mo. - The Missouri Department of Conservation (MDC) reports that it sampled and tested more than 37,000 deer for chronic wasting disease (CWD) during the 2023 CWD surveillance year between July 2023 and April 2024. Of the more than 37,000 deer sampled, 162 tested positive for CWD.

CWD is a 100% fatal disease in white-tailed deer and other members of the deer family. The disease has been attributed to significant deer population declines in other states and threatens Missouri's deer population, hunting culture, and economy. Learn more at mdc.mo.gov/cwd.

Those 162 deer bring the total number of CWD cases found in the state to 572 since the first case in wild deer was confirmed by MDC in early 2012. Including recent sampling efforts, more than 280,000 tissue samples from wild deer have been collected for CWD testing in Missouri since MDC began CWD surveillance in 2002.

Nearly 20,700 of the 37,000-plus deer tested this past CWD surveillance year were sampled as part of MDC mandatory CWD sampling efforts in select counties during the opening weekend of the November portion of firearms deer season, Nov. 11 and 12. Most of the remaining samples resulted from MDC's voluntary sampling efforts conducted throughout the deer season in partnership with taxidermists and meat processors and through freezer head-drop locations throughout the state.

Of the more than 37,000 samples, about 4,600 were collected during MDC's targeted removal efforts. MDC staff and staff from USDA Wildlife Services conducted targeted removal efforts in cooperation with landowners on a voluntary basis after the close of regular deer season in localized areas near where CWD has been found. Through targeted removal, 51 CWD-positive deer were removed to help slow the spread of the disease.

"The goal of targeted removal is to remove CWD-positive deer from the landscape and reduce deer density in these localized areas to slow the spread of the disease and protect Missouri's deer herd," explained MDC Wildlife Health Program Supervisor Deb Hudman. "Targeted removal is a proven method to slow the spread of CWD, and Missouri is one of several states that uses it to manage the disease."

Of the deer tested during the 2023 surveillance year, MDC found CWD-positive deer in 27 counties: Adair (3), Barry (1), Barton (15), Carroll (2), Chariton (4), Clark (1), Crawford (3), Dallas (4), Franklin (23), Grundy (1), Jasper (1), Jefferson (15), Linn (9), Macon (7), Maries (1), Oregon (4), Osage (3), Perry (3), Polk (2), Pulaski (1), Putnam (3), Randolph (4), Scotland (3), Ste. Genevieve (31), Stone (7), Sullivan (2), and Taney (9).

"This past year, we found CWD in a number of new counties," Hudman said. "Cases were detected for the first time in Chariton, Clark, Grundy, Jasper, Maries, Osage, Randolph, and Scotland counties."

She added that the goal of CWD management in Missouri is to slow the spread while researchers work to develop a cure and additional management tools, and to keep the percentage of infected deer low.

Although the number of CWD-positive counties increased this past year, Hudman noted that CWD management efforts have kept infection rates low. Less than one percent of tissue samples from hunter-harvested deer tested positive for CWD this past year.

"That is good news," Hudman said. "It is a testament to our ability to find the disease early in new areas and apply management actions to slow its spread."

Although CWD infection rates are low in Missouri, Hudman noted that this is exactly when aggressive management efforts must be implemented. "By the time CWD infection rates get high in a deer population, there is little that can be done to slow its spread. The time to act is now," she said.

She added that if MDC does not continue to act aggressively to slow the spread of the disease through management efforts such as targeted removal, CWD will spread faster and could have significant effects on the state's deer population, hunting culture, and economy.

"There are areas of the country where over half of hunter-harvested adult bucks test positive for CWD," Hudman explained. "We must do everything we can to not let this happen in Missouri, and we need the help of hunters and landowners in this critically important fight."

Hunters and landowners are critical partners in the fight against CWD and can assist MDC by continuing to deer hunt, by participating in CWD sampling, by following regulations designed to slow CWD spread, and by cooperating with targeted removal efforts. Learn more at mdc.mo.gov/cwd.