Tests spurs CWD initiatives

Dan Hansen
Now Media Group


When the Wisconsin Department of Natural Resources reported that 295 deer of more than 3,100 tested in 2015 had chronic wasting disease, some state legislators, wildlife groups and others called for more aggressive management efforts.

The reason for the renewed level of concern is that the numbers represent a record-high 9.5 percent of animals with CWD despite a record-low test sample.

Since its discovery in a captive mule deer in Colorado in 1967, CWD has been found in 23 other states and two Canadian provinces.

CWD is a disease of the brain and nervous system found in deer, elk and other members of the deer family. So far, there is no reliable live test for the disease. Infected animals may not show any symptoms, but in later stages they may begin to lose control of bodily functions and display abnormal behavior such as staggering. However, these symptoms also can occur in other diseases affecting deer and elk.

The Wisconsin DNR began monitoring the state's wild deer for CWD in 1999. The first positives were found in 2002 through testing of hunter-harvested deer in November 2001.

During the intervening years more than 193,000 deer have been tested in Wisconsin, more than any other state.

Deer farmers gather, share research

CWD, and efforts to contain it, also are of considerable interest to the state's more than 420 deer farms, many of which are represented by Whitetails of Wisconsin, a nonprofit organization whose mission is to promote Wisconsin's whitetail deer farmers and this specialty livestock industry.

'The overall economic impact of deer and elk farming in Wisconsin is $75 million,' said WOW vice-president Laurie Seale.

'Our goal is to help educate those interested in raising whitetail deer and share information regarding whitetail deer breeding, production and health care,' said added.

Part of that educational process is disseminating research that looks at the effects of CWD, while taking into account other factors that affect the overall deer population.

To those who suggest deer farmers are not using science, Seale responded, 'We've been using science developed by researchers over the last 40 years.'

National research

Dr. Michael Miller, senior wildlife veterinarian with the Colorado Division of Parks and Wildlife, has focused his research on CWD for the past 20 years

'We've studied the disease and followed the numbers, in part because there are a number of other things that influence particularly deer population dynamics a lot more than a disease like this would in the short-term: weather events, our own hunting practices, predation,' said Dr. Miller.

The Arkansas Game and Fish Commission recently confirmed that CWD has a prevalence of 23 percent in two counties. Of 256 randomly collected wild deer, 62 were found to have the disease.

'How did Arkansas not know they had CWD if their infection rate is over 20 percent?' Seale wondered. 'If deer and elk were actually dying of CWD, Arkansas would have known long ago they had CWD. Their infection rate is 2½ times what Wisconsin's is so that tells us they have had CWD for at least 20 years or more.'

Seale cited a study that shows the genotypes of the elk and how long they live with CWD on a highly infected research facility.

'The most susceptible to CWD live an average of 4 years,' she said. 'When it comes to the most resistant LL animals, they can't even say when or if they die, and this has been documented since 1970.

'Research also has shown that deer have a longer incubation period than elk so it's hard to say how long deer will live with CWD before dying of the disease, she added.

WWF takes aim at deer farms

The Wisconsin Wildlife Federation (WWF), composed of 195 hunting, fishing and trapping clubs, weighed in on the issue. In a letter sent to Gov. Scott Walker in early May, WWF called for more restrictions on the state's deer farms.

WWF's recommendations included requiring:

·All deer farms to have exterior double fencing;

·A DNR or independent annual inspection of all exterior fencing;

·Farms to inspect their exterior fences monthly and immediately after any major storms;

·Warning devices to detect open exterior fence gates;

·Cervid farms to have liability insurance sufficient to cover any damages, including to the wild deer herd, and;

·Any infected farms without double fencing to be totally depopulated within 30 days.

WWF also called for increased DNR and Department of Agriculture funding to regulate CWD, along with substantially increased transparency in distributing information on its spread and intensity in the wild herd and incidents of escapes from captive farms.

Regarding double fencing, Seale said, 'We need something that we can all live with, and double fencing would put the majority of us out of business. Deer farm escapes are rare and generally low risk.'

Seale explained that CWD is often found first on the farms because all deer there are tested. 'Then if they find it in the wild around a farm, they blame us,' she added.

Walker proposals

Addressing CWD at the recent 82nd Annual Conservation Congress meeting in Manitowoc, Gov. Scott Walker said, 'Managing our natural resources and preserving our hunting heritage is a delicate balance. By working together, we are taking actions and will continue to assess and update our chronic wasting disease plan to make sure we are doing everything we can to contain and address this complicated disease.'

Steps being taken to update the plan, include:

·Seeking input from hunters, landowners, farmers, and foresters in every county using County Deer Advisory Councils (CDACs);

·Directing the Department of Natural Resources (DNR) to conduct a comprehensive study of deer population dynamics;

·Creating Best Management Practices for the deer farm industry;

·Conducting more frequent fence inspections; and

·Developing quicker test results for hunters.

'In the face of the continuing threat to our deer population, we must take a multi-faceted approach to fighting this disease and work in a bipartisan fashion to modify regulations to keep hunters in the woods and, at the same time, manage our valuable natural resources,' Walker said.

Gov. Walker also is directing DNR to invest in research to understand the effects of CWD on the deer population by conducting a study – the largest and most comprehensive of its kind in Wisconsin history.

New approach

'When the DNR's go in and try to kill out an entire population like they tried in Wisconsin, they could be killing off the animals that are highly resistant to CWD,' Seale said. 'If these animals are living, on average, for four years, they are going to repopulate and be killed by a hunter long before CWD will ever affect them.'

She noted that a new $10,000 research project has begun on a small deer farm in southern Wisconsin. 'USDA personnel recently tranquilized all the animals and collected live tissue samples so they can determine their genotype and if they have CWD. The animals will them be monitored to see how long they live, and if they die from CWD.'

Seale also related that Dr. James Kroll (Wisconsin's Deer Trustee) spoke about the proposed study Governor Walker is planning at the Conservation Congress.

'They are planning to radio collar deer in the core zone and genotype them to determine if the genotype is changing to adapt to CWD,' she explained. 'We are very glad they are finally going to try and study the effect of CWD rather than killing healthy animals to determine if they are sick. This study will help tremendously to show if CWD is indeed having any effect.'