No additional Chronic Wasting Disease detected in remaining depopulated deer on Winona County farm

A Winona County deer farm went through a mandatory herd depopulation in October, and no Chronic Wasting Disease (CWD) was detected in any of the 120 white-tailed deer tested. The Winona County farm had been quarantined since October 2020 because of its connection to other Minnesota CWD positive farms. In August 2022, CWD was confirmed in a 4-year-old doe in the herd (https://www.bah.state.mn.us/news_release/cwd-confirmed-in-quarantined-winona-county-deer-herd/). A total of three CWD positive deer have been confirmed on this farm when two deer harvested after the August detection also tested positive for CWD.

“Unfortunately, we rarely find a definitive answer to how CWD was introduced into a herd. We will continue to work with farmers and state and federal partners to better understand how these animals were infected,” said Senior Veterinarian Dr. Courtney Wheeler. “We’re fortunate this producer is interested in solving this puzzle and is working with us, the USDA and the University of Minnesota on further research. Tissues from the depopulated deer will be submitted for a federally funded genomic testing project to understand if some deer are more susceptible to CWD than others.”

The Winona County herd actively participated in the national CWD Herd Certification Program since 2012 and tested more than 100 deer for CWD before the disease was detected in August 2022. The herd was in a CWD endemic area of Minnesota where there is a high prevalence of CWD in the wild deer population. The farm and deer enclosures had been double fenced since 2015.

As part of an agreement with state and federal animal health officials, the herd owner is required to clean and disinfect all enclosures and must maintain fencing on the property for five years from the date of the last detection. The farm is not allowed to have any deer or elk for five years, and the property owner must maintain fencing to prevent wild deer from accessing empty pens. Biohazard signs will be posted on the fencing and must be maintained for the entire five-year fallow period.

CWD is a disease of the deer and elk family caused by prions, which can damage brain and nerve tissue. The disease is most likely transmitted when infected deer and elk shed prions in saliva, feces, urine, and other fluids or tissues. CWD is not known to naturally occur in other animals. The disease is fatal in deer and elk, and there are no known treatments or vaccines. According to the CDC, consuming meat from a CWD positive animal is not advised.

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