A deer raised on a Ramsey County farm has tested positive for chronic wasting disease (CWD), a fatal brain and nervous system disorder that affects elk, deer and moose.

It is one of only a few detections of the disease in Minnesota in the past 10 years. There is no known cure for the disease, which is contagious among animals..

The state Board of Animal Health announced the positive finding on Friday and placed the farm where the 2-year-old red deer was raised and died on May 10 -- a model operation with about 500 red deer, according to board director Dr. Paul Anderson -- under quarantine.

The finding raises concerns that the CWD could spread to Minnesota's wild white-tail deer, as well as to 13,000 elk, red deer and white-tail deer in 532 farm herds.

The disease is thought to be caused by an abnormal protein in the nervous system cells of elk, deer and similar antlered animals. There is no evidence it is transmissible to humans.

There's no reason to believe any wild deer in Ramsey County have been infected, said Lou Cornicelli, the Minnesota Department of Natural Resource's wildlife research manager.

But Cornicelli said the agency now will test white-tailed deer killed by vehicles, hunters and municipalities for CWD. Ramsey County parks hold archery hunts in the fall to reduce deer numbers, and North Oaks has a deer-control program too, Cornicelli said.

The only wild white-tail in Minnesota with CWD was killed by a bow hunter near Pine Island in 2010, near where farm elk were found with the disease. Last year, the DNR tested about 2,400 deer killed by hunters, and found none with CWD. Over the years, Minnesota has tested more than 30,000 deer for CWD, most of them wild deer killed by hunters. The tests can be performed only on dead animals.

Anderson said animal health and DNR officials, as well as state and federal agriculture officials, will meet with the farm owners to discuss what to do next. Entire farmed herds in which CWD has been detected have been slaughtered, but that is not necessarily what will happen in this case.

Anderson said the owners have registered their animals with the state and regularly tested them since 2000, four years before that was required in Minnesota. They raise the animals for breeding, to be sent to game farms and for meat.

"They've never missed an animal they were supposed to test," Anderson said. "Their fences are immaculate. They're very, very good caretakers ... . This is a sad event, really, that this herd was found to be positive."

mcaul@startribune.com • 612-673-7646 doug.smith@startribune.com • 612-673-7667