
Officials have confirmed chronic wasting disease (CWD) —an always-fatal prion disease that affects members of the deer family (cervids)—on a deer farm in Rock County, Wisconsin, according to a news release yesterday from the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP).
The positive result came from a 5 1/2-year-old doe. Test results were confirmed by the National Veterinary Services Laboratories in Ames, Iowa. Rock County is south of Madison, the state capital, on the Illinois border. One other deer farm in the county had CWD confirmed on its premises previously but remains in operation.
Farm under quarantine during probe
The newly affected deer farm is quarantined while DATCP and US Department of Agriculture scientists conduct an epidemiologic investigation. The DATCP regulates deer farms for registration, recordkeeping, disease testing, movement, and permit requirements.
Wisconsin has 142 registered deer farms and hunting ranches, 10 in Rock County, according to DATCP data. From 2001 through October 2024, 46 of the locations (32%) tested positive. Twenty-four of the affected farms depopulated their herds.
CWD is a slow and progressive neurologic disease of cervids caused by an infectious protein called a prion that affects animals' brains. No human cases have yet been confirmed, but health officials warn the public not to eat the meat of infected animals.