520,000 Missourians hunt deer each fall.
Their livelihood could be threatened by chronic wasting disease, also known as CWD.
According to the Missouri Department of Conservation, CWD is only found in animals in the deer family, otherwise known as cervids, but has no known treatment or vaccine, and it can spread very quickly.
So far, 21 cases have been confirmed in Missouri since 2010, mainly in Macon in Linn counties.
11 of those cases were found in captive deer in private hunting preserves, and 10 cases in free-range deer near those facilities.
The disease is caused by an infectious protein, and is spread through urine, feces, saliva, and tissue of the animal.
"The challenging thing with this disease is that the incubation period which is the time from when the animal is infected to when they actually show symptoms can vary widely. It could be up to years before they show any signs," said Dr. Kelly Straka, a state wildlife veterinarian for the Missouri Department of Conservation.
Signs an animal has CWD include the emaciation, disorientation, and excessive drooling.
While the disease is not known to be contagious to humans, it's recommended that the infected deer not be consumed.
"The big question that I think a lot of people are trying to figure out is what are the long term impacts of this disease. Especially since it is 100% fatal that we know of...any animal that does contract this will die. We're concerned about the long-term health of the population," said Straka.
If the disease continues to spread, it could disrupt thousands of jobs and businesses that depend on the $1 billion in economic activity related to deer hunting.
The MDC is continuing to test deer for CWD in it's containment zone which includes Adair, Chariton, Linn, Macon, Randolph, and Sullivan counties. If you harvest a deer in one of these counties, you can get it tested for CWD at one of the sites listed on this site.