Five Answers about CWD

Steve Sorensen
Steve Sorensen
Contribiting Writer

I’m probably not the only outdoor writer who is reading everything he can about Chronic Wasting Disease, and I’m reading literature beyond the world of whitetail deer. As I’ve studied the issue I’ve come up with several questions. Some questions have answers.

1. Is CWD a unique disease?

No. Chronic Wasting Disease is a disease specific to deer, but it is not unique. Every animal in the cervid family can get it, from whitetails to moose to exotic deer, but many unrelated species get similar diseases with virtually the same effects.

Sheep scrapie, discovered in the mid-1700s, is similar. So is Mad Cow Disease, a big issue in England in the 1980s. Mad Cow (Bovine Spongiform Encephalopathy, or BSE) is believed to have come from food pellets infected with sheep scrapie. Mink, camels, cats and exotic ungulates can get similar diseases, and so can humans. In humans it’s called Creutzfeldt–Jakob Disease, or CJD, which has several variants. All are forms of Transmissible Spongiform Encephalopathy (TSE), and science has not yet found a cure for any of them.

2. Do deer really die from CWD?

Yes. The claim that deer do not die from CWD persists, but it’s an absolutely false claim. The rumor survives simply because people are seldom present when a deer dies in the wild. Even if no one ever witnessed a deer die from CWD (although a few have), we would know they die because all TSE diseases are neurodegenerative — they destroy nerve tissue. No animal or person has ever survived a TSE disease.

CWD is always fatal unless something else kills the deer first. All TSE diseases cause the victim’s brain to become sponge-like until the animal becomes lethargic, confused, and unable to meet its basic needs. It ultimately dies, or makes death from other causes more likely. It may get hit by a car, harvested by a hunter, or killed by a predator.

3. Is CWD really caused by a prion?

Maybe not. All TSE diseases are called prion diseases. A prion is an abnormal protein defined as a “proteinaceous infectious particle,” but it is not infectious and cannot conventionally reproduce because it has no DNA. Prions were discovered in the early 1980s, but how they replicate or how they cause healthy proteins to transform into prions is still uncertain. Many questions about prions remain unanswered, but the prion theory is the dominant assumption.

Prions are always present in TSE diseases, but if they aren’t the cause, what is? Dr. Frank Bastian of the University of New Orleans believes a bacterium is the cause. He finds a specific spiroplasma bacteria present in every case of TSE he has studied. Dr. Laura Manuelidis of Yale University is researching a viral cause. Until the discovery of prions, TSE diseases were included in a class of diseases called slow viruses. If either of these scientists is correct, the prion is probably an indicator of the disease, but not the direct cause.

4. Will a cure for CWD come from deer biologists?

No. Deer biologists are unlikely to find a cure for CWD because few (if any) deer biologists are working on a cure. However, deer biologists are not idly sitting on the sidelines. Most are trying to limit the spread of the disease while waiting for a cure.
The work deer biologists do is still vital. If they do not mitigate the spread of the disease, delivering a cure will be much more difficult if not beyond hope. Even if captive animals can be cured, curing free-ranging animals will be much more challenging for our biologists.

5. Should we look beyond the deer world for a cure of CWD?

Yes. We should not discredit researchers outside the world of wildlife. Bastian and Manuelidis suffer such criticism. Hunters ask, “If these scientists are not deer researchers, how can they contribute to a CWD cure?” That question belies a misunderstanding of the disease itself. Any progress made in solving the problem of Creutzfeldt–Jakob disease or any other TSE will benefit CWD research and all other species that are susceptible to TSE diseases. That’s why everyone in the deer world must be open to a cure from outside.
When “The Everyday Hunter” isn’t hunting, he’s thinking about hunting, talking about hunting, dreaming about hunting, writing about hunting, or wishing he were hunting. If you want to tell Steve exactly where your favorite hunting spot is, contact him through his website, He writes for top outdoor magazines, and won the 2015 and 2018 national “Pinnacle Award” for outdoor writing.