As CWD probe continues, another opens
Deer disease likely detected early in South Texas county, but Hill Country breeding facility recently tests positive
The detection of chronic wasting disease prompted swift containment action and an investigation in Val Verde County.
Wildlife officials are cautiously optimistic they caught CWD early while it exists at a low prevalence in the South Texas county and does not have far-reaching geographic impact.
An initial wave of testing yielded one additional positive out of 465 samples. That second infected deer was found within two and a half miles of the one that was confirmed to have CWD in December.
“We still do have some gaps in the sampling ... but it does offer some hope that the geographic extent of the disease is small and the prevalence of the disease, at least over the currently delineated zones, seems to be quite low,” said Mitch Lockwood, Texas Parks and Wildlife Department’s big game program director.
Containment and surveillance zones were set up after a free-ranging 5½-year old white-tailed doe tested positive for CWD. The discovery was the first case of CWD in Val Verde County.
Hunters were required to report harvests taken in either zone to CWD check stations within 48 hours. A prohibition on the transportation of live deer was implemented and restrictions were also placed on the movement of carcasses.
City and county officials also worked to locate as many roadkills as possible for testing. Sampling is lighter with deer season now concluded, but Lockwood said a dozen to 20 animals are sent out to be tested each week.
While wildlife officials are interested in gathering more surveillance from the immediate area of where the two deer with CWD were located, it is also important to continue to assess the entirety of both zones.
“We’re going to continue to surveil that area in the future,” Lockwood said. “And the more of those gaps we can fill, then the more confidence we can establish that the prevalence and geographic extent are as small as it appears to be at this time.”
A public meeting is being planned for the coming weeks in Del Rio with a date to be determined.
The investigation into CWD in Val Verde County continues to develop. In Kimble County, another one launches.
A 5½-year old whitetailed deer in a Hill Country breeding facility tested positive for CWD, TPWD announced Thursday. The case marks the first instance of CWD in the county.
“The Texas Parks and Wildlife Department is working in coordination with the Texas Animal Health Commission and other agencies to launch an epidemiological investigation to determine the extent of the disease, assess risks to
Texas’ free ranging deer and protect the captive deer breeding industry,” TPWD wildlife veterinarian Bob Dittmar said in a release.
The investigation is in the early stages, so little is known, but officials have moved to secure the animals at the affected facility. The site is under quarantine and no deer can be moved. Facilities that have exchanged deer with the Kimble County facility in the last five years are also under deer movement restrictions.
The investigation could potentially expand to areas outside the breeding site.
“We do think it would be prudent to establish a surveillance zone around that facility,” Lockwood said. “In that zone we would have movement restrictions for live deer, (and) we’d have movement restrictions on carcass parts of hunter-harvested deer moving forward. And there would be mandatory testing requirements of hunter-harvested deer.”
Breeding facilities do account for most of the positive CWD tests in Texas, with 129 of the 169 cases of infected cervids coming from breeding facilities or their release sites. The nature of the sites, with high concentrations of animals in an enclosed environment, can exacerbate the spread of the disease.
However, the Kimble County case is perplexing in the early stages of investigation.
The breeding facility has been functioning since 2011 and has a clean CWD track record. Breeding facilities raising whitetails or mule deer are required to test 80 percent of adult mortalities in order to maintain compliant status, as well as requisite testing for live deer. Breeding facilities cannot move deer without meeting the minimum requirements.
These measures were put in place in response to the discovery of CWD at a Medina County breeding facility in 2015, the first case of CWD in whitetails in Texas. The first case of CWD in the state was found in a free-ranging mule deer in far West Texas in 2012.
Officials aim to ascertain the extent of the disease inside the facility, but it is possible that the Kimble County deer could have been infected from the outside, given the site’s history of compliance.
“This breeding facility has been established for quite a few years,” Lockwood said. “Our records indicate that they’ve tested a high percentage of their mortalities over the years, and they haven’t introduced new deer for a few years.”
Both counties’ cases present distinctive scenarios.
In Val Verde County, located along the U.S.-Mexico border in the southern Edwards Plateau and on the southern edge of the South Texas Plains, the infected deer was free ranging, with no indication that it could have come from a breeding facility. The deer was found in a subdivision and in an area where barriers like Lake Amistad and suburban environments could restrict movement and help wildlife managers contain the disease.
Kimble County is a little less than a 2½-hour drive northeast from Val Verde, closer to the heart of the Edwards Plateau. The area is more rural and wide-open.
High fences are prevalent in the Hill Country and Lockwood said that those barriers, like in Val Verde, could be beneficial in managing the disease.
“Every situation that we have in Texas is different from any of the others, but the way to manage them may not be all too different,” Lockwood said.
CWD is a neurological disease that affects cervids like deer, elk and red stag. It is always fatal and has no cure. Eradication is thought to be impossible once the disease becomes established.
Symptoms include drooling, listlessness, weakness, lack of mobility and excessive thirst and urination. The disease is caused by prions, or misfolded proteins, that inflict brain damage. Those prions can be spread through bodily fluids like blood, urine and saliva, nose-to-nose contact or environmental contamination in soil, food and water.