Lane Laning: CWD in Deer Can Be Managed

With chronic wasting disease popping up in deer and elk in a number of states across the country, including this year in Michigan, the debate is often driven by finger-pointing and scary predictions. But an even-keeled analysis of the facts behind CWD and its spread reveal that this is a problem that can be managed.

The question of how CWD spread throughout the country to 20 states is a good starting point for discussing how to manage it. The disease was first found in Colorado in the 1960s, and subsequent findings of CWD in neighboring states is likely due to the transmission and movement among free-ranging deer over subsequent decades.

How did CWD spread to areas that are farther away? The transport of deer for repopulation programs is one apparent means. Years ago, mule deer were taken from northern Colorado — ground zero for CWD — and used in southern New Mexico to help declining populations of the animal. The first case of CWD in Texas came from animals that entered from New Mexico. It’s unlikely that this is a coincidence.

Recognizing the potential for CWD to spread through interstate transport of deer, the government developed regulations for interstate transfer of deer and elk about 15 years ago. Game farms that raise deer and elk and ship them across state lines are required to participate in the CWD Certification program administered by the USDA. The program requires that a facility test all deaths over one year of age for a minimum of 5 years, with no positive CWD tests, before its herd can be certified.

However, there are still loopholes. Hunters transporting carcasses across state lines is one way that CWD could spread. Another is through elk relocation programs, which have moved elk from CWD-positive areas to Kentucky and other states without following the federal herd certification protocol. Lastly, new research demonstrates that CWD can be spread by plants; transport of hay and other roughage could unwittingly spread CWD.

There are a number of challenges, but the good news — I use the term loosely — with CWD is that the effects on deer population appear to be negligible. This may sound strange given the scary scenarios that have been thrown about, but the research appears solid.

Researchers at the University of Wisconsin studied CWD’s effect on the wild deer population and “found no evidence that CWD was substantially increasing mortality rates during the duration of our study from 2003-2007” (CWD was first discovered in Wisconsin in 2002). Similarly, researchers at Colorado State University found that “although CWD may affect mule deer recruitment, these effects seem sufficiently small that they can be omitted in estimating the influences of CWD on population growth rate.”

More likely to affect deer and elk populations are predators (such as the growing wolf populations), vehicles (which conservatively kill hundreds of thousands of deer), drought, and other diseases such as bluetongue.

While there are many challenges with CWD we do have time to take them on. CWD does not affect humans or livestock and takes years to kill a deer or elk (if the animals don’t die of something else first). However, there is no live-animal test for CWD, meaning that authorities are left with a reactionary position of having to test harvested or road-killed animals. Additionally, states don’t test many free-roaming deer for CWD — generally less than 1 percent of the state’s total deer population.

Testing more wild deer and elk for CWD is a good first step. But researchers are working on live-animal CWD tests and vaccines. These programs need funding from all stakeholders and will take time to develop, but offer promise in fighting CWD.

Too many irresponsible claims are being made about CWD. The sky is not falling. CWD is a problem that we can manage, but only if we have the right attitude.

SOURCE: Lane Laning, The Times Herald