Testing is just getting under way and already preliminary results suggest as many as six northwest Kansas deer might have been suffering from chronic wasting disease.

The presumptive positive tests come early in the testing schedule, from animals either killed by bow hunters of those that had been showing clinical signs of CWD -- transmissible spongiform encephopathy, similar to mad cow disease.

The six deer came from Decatur, Rawlins, Sheridan, Graham and Thomas counties, according to KDWP spokesman Mike Miller.

That represents the addition of two counties -- Graham and Thomas -- where CWD has been discovered in free-ranging deer.

It also represents the first time a deer has been killed and tested because it was showing clinical signs of the disease. In the past, none of the animals testing positive were showing any signs of the disease.

Miller said one or two of the deer initially showing up as positive had displayed signs of the disease. CWD is a slow-developing disease, taking as much as two years to even be discernible in laboratory tests.

The first case of CWD in a free-ranging deer came from Cheyenne County in 2005. Three additional deer were determined to have CWD in 2007, all of them from Decatur County, and 10 tested positive from 2008's hunting season. Those 10 came from Cheyenne, Rawlins, Decatur and Sheridan counties.

This year's preliminary findings at Kansas State University's School of Veterinary Medicine still must be confirmed by follow-up testing at the National Veterinary Services Laboratory in Ames, Iowa.

Results from that second tests are extraordinarily slow to be returned, KDWP said.

Generally, the Kansas Department of Wildlife and Parks doesn't acknowledge the preliminary results, because there is always a chance for what is called false-positives in the test used by KSU.

So far, however, all preliminary tests have been confirmed by the more expansive tests in Iowa.

Hunters whose deer test positive are notified as soon as the KSU results are returned.

About 2,000 samples have been collected statewide, most of them from the eastern half of the state.

Money from a federal grant is used to pay for the tests conducted at KSU, which performs them at a reduced rate but at a slightly slower pace.

The advance of CWD is causing some changes in terms of what hunters should do and how it clicks with state law.

KDWP plans to bring up changes in the law that would let hunter bone out deer during antlerless-only seasons that have required leaving a head on a deer.

Because CWD prions are found in the brain and spinal column, hunters are told to leave that material where the animal was killed.