Some claim that CWD has always been present in our deer herds. They feel that just because we’re now testing for it and finding it, that wildlife managers are overreacting, and CWD won’t really have a major impact on our deer populations. Is this true?

All evidence of the last few decades indicates that this is not true. CWD follows a classic epidemiologic pattern where it shows up in an area, and slowly spreads from that “hotspot” while also increasing in prevalence within that population. The last 10-20 years of disease surveillance across the country has established this.

The spread of CWD within a population is slow and insidious. It can take a long time to reach a threshold, above which, actual impacts are observed. What has emerged in the last few years is that CWD-related mortality is now recognized as the major cause of population declines in some herds. We aren’t at that threshold in North Dakota yet and our aim is to never get there. Some research papers documenting this:

• Edmunds DR et al. 2016. Chronic wasting disease drives population decline of white-tailed deer. PLoS ONE. 11(8): e0161127.
• Monello RJ et al. 2014. Survival and population growth of a free-ranging elk population with a long history of exposure to chronic wasting disease. The Journal of Wildlife Management. 78:214-223.
• DeVivo MT et al. 2017. Endemic chronic wasting disease causes mule deer population decline in Wyoming. PLoS ONE. 12(10):e0186512.