Weekly Topic: MN Board of Animal Health CWD Updates
Gus Brihn

Farmed Cervidae Update

In the state of Minnesota, any person who raises deer or elk (cervidae) must register with Board of Animal Health and must meet all of Minnesota’s required statutes and regulations. Each year following registration, the Board of Animal Health will conduct inspections. In addition to monitoring for notifiable diseases such as Tuberculosis and Brucellosis, the board also pays close attention to Chronic Wasting Disease (CWD).

All farmed cervidae producers are required to test their herd for CWD. All farmed cervidae 12 months of age or older that die or are slaughtered on farms require testing and samples are sent to the University of Minnesota Diagnostic Lab. To maintain accurate surveillance, all movements of elk or deer from the herd is also monitored. In 2019, the Board of Animal Health established a new CWD sample collector training program for producers and veterinarians who want to submit their own samples. About 100 people participated in the first training program. The board will now require all individuals that want to collect CWD tissue sample from farmed cervids to have authorization.

There are three components to the training: classroom training, sample collection demonstration by field staff, and submission of two successful CWD samples to the Minnesota Veterinary Diagnostic Lab for testing in the remainder of 2019. Individuals who complete this training will be authorized to then submit samples.

BAH
MN Legislature (PDF)

Wild Cervidae update

Recently the Minnesota Department of Natural Resources (DNR) released a new CWD surveillance and management plan. The general plan explains the threat of CWD in wild deer, elk, and moose populations throughout the entire state. The response plan addresses the management of wild cervidae and not cervidae living or raised in captivity. It explains how the DNR views the threat of CWD in Minnesota’s wild cervidae population, incorporates current research and scientific literature including expert opinions and from other U.S. states and Canada, and includes information specific to CWD infections that may persist on the landscape if the disease becomes endemic.

In response to the positive case found in Crow Wing County, the DNR increased special hunting boundaries. In addition, shooting permits with deer tags were mailed to landowners with greater than 20 acres of land and will be working with willing landowners to allow the U.S. Department of Agriculture (USDA) to remove additional deer on their properties.

Aerial survey done have shown that it is extremely difficult to reduce wild deer numbers significantly despite an aggressive response. Targeted culling operations in conjunction with USDA are effective but expensive. However, nothing goes to waste. All venison received from the culls that test negative for CWD is donated and given to the public through share the harvest program.

DNR: Response Plan (PDF)
DNR

CWD testing and transmission update

The current gold standard test to diagnose CWD is Immunohistochemisty (IHC). From sample collection to diagnosis usually takes about two weeks. Testing requires the submission of the brainstem and lymph nodes which are submitted in a 10% formalin solution or fresh on ice. The problem is that this test takes time while the disease continues to spread across North America.

The University of Minnesota is developing a diagnostic tool that would allow wildlife managers to get ahead of the disease. The tool is called flow cell. Flow cell would allow for rapid testing, similar to how one could use a pregnancy test, where fluid is analyzed by a camera on the device which then processes it and produces a diagnosis.

Current available diagnostic tests are lacking, expensive, time consuming, limited to certain sample types, and prone to false negative and false positive. Currently flow cell is being used in human medicine to analyse Alzheimer’s and Parkinson’s disease. Flow cell would take an hour or two compared to the two weeks.

MPR

Gus Brihn

Gus Brihn

Gus completed his undergraduate degree at the U of M in Global Studies, and has spent much of his time abroad, including time in France and Namibia. Gus became interested in emergency medicine from becoming a Wilderness First Responder and NR-EMT. He completed his veterinary degree at the University of Glasgow in Scotland. Gus is interested in zoonotic disease outbreak investigation, prevention, and epidemiology. Outside of work, Gus enjoys rock climbing and doing Brazilian Jiu jitsu. He has an 11 year-old Staffordshire terrier mix breed dog named Sweet Pea.