Sightings of the deers suffering chronic wasting disease have spread to several parts of the United states. This brain infection is affecting herds of deer, reindeer, moose and elk. It has been found in some areas of North America, including Canada and the United States, Norway and South Korea. It may take over a year before an infected animal develops symptoms, which can include drastic weight loss (wasting), stumbling, listlessness and other neurologic symptoms. CWD can affect animals of all ages and some infected animals may die without ever developing the disease. 

This chronic wasting disease (CWD) is a transmissible spongiform encephalopathy, meaning the deer are exposed to a pathogen (a protein called a prion) that causes holes throughout the brain, making the organ look like a sponge by the time of death.

Though the CWD prion doesn’t seem to be able to infect humans or other livestock now, the COVID-19 coronavirus crisis has shown how easy it is for some microorganisms to jump the species barrier. This is easier with close contact between infected animal populations and humans, as is the case with deer farming and hunting.