Oregon is one of the last remaining safe zones from chronic wasting disease, a fatal illness that has killed tens of thousands of deer, elk and moose across North America. Of the western states, only Oregon, Nevada and Arizona have yet to register a case.

And now research suggests that at least some animals in Oregon may have a natural genetic resistance to the disease.

Chronic wasting disease (CWD) affects members of the deer family, spreading through close contact between animals. There isn’t a cure, and those infected experience extreme weight loss, also known as wasting, loss of coordination, and drooling. It’s always fatal.

CWD is a neurologic disease caused by infectious proteins called prions that are also responsible for diseases like Creutzfeldt-Jakob in humans and mad cow disease. But unlike mad cow disease, there isn’t evidence that CWD can spread to humans.

Chronic wasting just recently arrived in the Pacific Northwest. It was detected in Idaho for the first time in 2021 and in Washington in 2024.

So far, Oregon has been spared, but it’s only a matter of time. The Oregon Department of Fish and Wildlife predicts the disease could cause major declines in deer and elk populations in the state. The agency is working with hunters to test and monitor for CWD introduction on the ground.

But there’s new evidence that the eventual spread of CWD in Oregon may be slowed because of genetic good fortune.

Researchers from ODFW, the University of Illinois Urbana-Champaign, and the U.S. Fish and Wildlife Service Forensics Lab in Ashland conducted genetic testing on 183 elk across Oregon. They found that a large percentage of the two subspecies have a genetic variation associated with resistance to the disease.

Testing showed 42% of Oregon’s coastal Roosevelt elk and 49% of the Rocky Mountain elk had the genetic marker. The study authors say these rates are higher than they’ve seen in other states.

“Without advantageous genetic variants, a whole population can be wiped out fairly quickly,” University of Illinois researcher Alfred Roca said in a university announcement. “It’s not enough to prevent the spread of CWD once it enters the state, but it may slow it down a bit.”

These biological speed bumps could give wildlife managers more time to prepare and to step in to control the disease when they find infected animals.

The research is published in the Journal of Heredity here.

In these All Science Snapshots, “All Science. No Fiction.” creator Jes Burns features the most interesting, wondrous and hopeful science coming out of the Pacific Northwest.

Find full episodes of “All Science. No Fiction.” here.

News Source : https://www.opb.org/article/2026/01/22/oregon-elk-show-genetic-resistance-chronic-wasting-disease/