CWD-positive deer found in Crow Wing County
- General information
- Summary of necropsy findings for CWD-positive deer
- FAQs about the CWD-positive deer
General information
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The DNR has confirmed chronic wasting disease in a wild deer in Crow Wing County. This test result marks the first time in Minnesota the always-fatal neurological disease has been found in a wild deer outside of the southeastern part of the state.
The DNR is targeting a localized area to remove infected deer. It is offering landowner shooting permits and working with willing landowners to allow the U.S. Department of Agriculture to remove additional deer on their properties. Landowner shooting permits have been mailed to landowners who have 10 or more acres and are located within 2 miles of where the CWD-positive deer was found. These permits went into effect on Saturday, March 2.
The DNR began surveillance around a CWD-positive captive cervid facility near Merrifield starting in the 2017 hunting season. With outstanding cooperation from hunters, the DNR has sampled more than 8,600 deer in its north-central surveillance zone during the past two years. None of those deer tested positive. Since this is the first positive wild deer found in the area, DNR is hopeful the disease is isolated.
Summary of necropsy findings for CWD-positive deer
The Veterinary Diagnostic Laboratory (University of Minnesota, St. Paul) received the deer on Feb. 11 for necropsy. After allowing the deer to thaw, Dr. Arno Wuenschmann performed the necropsy on Feb. 14. The deer weighed 100 pounds and was so emaciated that there were no internal fat stores remaining. The deer’s bone marrow was red and gelatinous, a further indication of potentially fatal poor nutritional state. There was also evidence of pneumonia that was caused by the aspiration of food. However this aspiration pneumonia was not deemed of sufficient severity to have caused the animal’s death based on the small portion of lung that was affected. Furthermore, one of the compartments of the stomachs (abomasum) was distended and impacted with food. Additional IHC testing at Michigan State University of the brain stem (the obex) also found CWD on Feb. 27.
Dr. Wuenschmann’s conclusion is that the animal had CWD based on the detection of abnormal prion protein in the obex by immunohistochemistry, which corroborated the previous diagnosis of CWD made at Colorado State University. Both emaciation and aspiration pneumonia are common findings in deer with CWD.
Complete details are available in the Veterinary Diagnostic Laboratory necropsy report.
For questions related to the postmortem examination of this case, please contact: Dr. Arno Wuenschmann, DVM, ACVP, University of Minnesota: 612-625-8787 or [email protected].
For questions related to any other aspects of this case, please contact: Dr. Michelle Carstensen, Wildlife Health Program Supervisor, Minnesota Department of Natural Resources: 651-539-3309 or [email protected].
FAQs about the CWD-positive deer
What was the timeline after the deer was reported?
- Jan. 23, 2019: An adult female white-tailed deer was found dead near Merrifield by a private citizen and reported to a DNR Conservation Officer. The officer brought the carcass to the Brainerd Wildlife Office for CWD testing. The deer was noticeably thin. Retropharyngeal lymph nodes were extracted and stored frozen until they could be shipped to the Wildlife Health Program staff in Forest Lake.
- Feb. 4, 2019: The Crow Wing sample was shipped in a batch of 207 deer samples, mostly from a late season hunt in Winona County, to Colorado State University for testing.
- Feb. 8, 2019: The DNR was notified that this deer tested as “suspect” on the ELISA screening test.
- Feb. 14, 2019: CWD was confirmed by the immunohistochemistry (IHC) test.
- Feb. 15, 2019: The DNR announced the findings publicly.
Why did the DNR test this deer?
Because of the CWD-positive captive cervid facility, there is a high degree of public awareness about potentially sick deer in the area. Given the deer was found dead very close to the positive farm, it was important to test this animal for CWD.
What was the sex and age of the deer?
The deer was an adult female. Since the deer was frozen solid, a section of the lower jaw was cut off to thaw and a front incisor was extracted. This tooth will be sent to Matson’s Laboratory (Manhattan, MT) for aging by cementum annuli technique to provide an age estimate of this deer.
What happened to the carcass?
After sampling, the carcass had been placed in a dumpster at the Brainerd Wildlife Office, to await transfer to a lined landfill, which is an approved method for disposal of deer carcasses.
What did you do when the test results came back?
Once the preliminary test results were received on Feb. 8, the Wildlife Health Program staff contacted Brainerd Wildlife staff to inquire if the carcass was still available. The dumpster had not been picked up and the frozen carcass was still there. The carcass was extracted from the dumpster and routed to the University of Minnesota’s Veterinary Diagnostic Lab for a full necropsy.
What happened to the deer after the necropsy?
The carcass was placed in the alkaline digester at the University of Minnesota.