Chronic wasting disease is beginning to concern state officials.

The Minnesota Board of Animal Health recently confirmed a third CWD-positive deer on a Meeker County farm near Dassel. The positive CWD samples came from a 2-year-old female white-tailed deer that died on the farm.

In accordance with state law, tissue samples were collected from the carcass and submitted for CWD testing. Farmed deer, 12 months of age and older, are required to be tested for CWD if they die or are slaughtered. MBAH has been working to fight the disease since the 1990s. Sporadic cases have been found on Minnesota cervidae farms since 2002, when an outbreak near Aitkin spurred laws that now require deer and elk farmers to test for the disease in any animal over the age of 16 months that dies.

CWD samples are tested at the University of Minnesota Veterinary Diagnostic Laboratory and forwarded to the National Veterinary Services Laboratory in Ames, Iowa, which officially confirms the disease.

MBAH records show the latest CWD-positive deer was born on the CWD-positive Crow Wing County farm and moved to the Meeker County farm in December 2014. As of Dec. 30, 2016, there are three confirmed CWD-positive farmed deer in Minnesota. Two are associated with the previously reported case in Crow Wing County. The third, and most recent, case in Meeker County in a herd of 14 white-tailed deer, which remain quarantined on the farm.

Animal ID, herd inventory key
“This is why it’s important for the board to maintain accurate animal identification and herd inventories,” says Paul Anderson, MBAH assistant director. “We were able to look back at five years of recorded deer movements out of the infected Crow Wing County herd, locate herds that received deer from it, and investigate those farms for a CWD infection. This tracing led to the discovery in Meeker County.”

On the Crow Wing farm, the original quarantine remains in place, where two female deer tested positive for CWD. MBAH has been reviewing animal movement records in and out of the herd during the past five years.

Movement records out of the herd show deer were moved to four other Minnesota farms during the five year trace-back period. One of those herds is the Dassel farm in Meeker County. All associated herds remain under movement restrictions.

CWD is a disease of deer and elk caused by an abnormally shaped protein, a prion, which can damage brain and nerve tissue. There is no danger to other animal species. The disease is most likely transmitted when infected deer and elk shed prions in saliva, feces, urine and other fluids or tissues. The disease is always fatal, and there are no known treatments or vaccines. CWD is not known to affect humans, though consuming infected meat is not advised.

At a recent Minnesota House Environment and Natural Resources Policy and Finance Committee hearing, Lou Cornicelli, Department of Natural Resources wildlife research manager, told lawmakers that a passive approach to controlling the disease would likely establish CWD in the state. Rather, the disease required aggressive action to eliminate it.

Cornicelli said the economic impact in Minnesota that comes from hunting and raising deer has been estimated at $500 million.

Anderson says there are currently 460 farms around the state that raise a total of 11,000 deer and elk.

Along with movement restrictions on the farms where chronic wasting disease has been found, farms within 10 miles of infected animals found in the wild are also quarantined. Five farms in southeastern Minnesota now have such limits in place.

Information about Minnesota's farmed deer and elk herds can be found on the MBAH website, bah.state.mn.us/deer-elk.

Sources: DNR and Minnesota House of Representatives Public Information Services