State seeks help from hunters in monitoring deer disease

By Shannon Tompkins Updated 8:40 pm, Saturday, September 26, 2015

In the wake of the discovery this summer of chronic wasting disease (CWD) in captive white-tailed deer in two fenced deer breeding/production operations in Texas, state wildlife officials are expanding a long-running program aimed at monitoring the state’s free-ranging whitetail herd for the fatal, untreatable, transmissible neurological disease.
In addition, the state’s 700,000-plus deer hunters are being asked to aid in that effort by volunteering tissue samples from whitetails they take during the 2015-16 hunting season.
That season begins Saturday with the statewide opening of archery-only hunting for whitetails and the opening of whitetail season on many tracts enrolled in Texas’ Managed Lands Deer Permit program. The general whitetail deer hunting season opens statewide Nov. 7.
“We’ve had a very robust CWD sampling program of hunter-harvested deer for years; we’ve collected and tested almost 30,000 samples,” Mitch Lockwood, director of big-game programs for Texas Parks and Wildlife Department, said, noting none of the samples from free-ranging whitetails has been positive for the degenerative disease that has proven transmissible among cervids such as deer and elk but has not been shown to be a health risk to humans. “This year, we’re going to be doing more than we’ve done before. We’ll be collecting samples from every area, but concentrating on getting larger numbers of samples from areas where assessments indicate risk levels are higher.”

7,600 samples targeted

Those higher-risk areas include counties where the two captive deer operations are located (Medina and Lavaca) and those around the 46 sites where deer tied to the Medina County breeding operation were released, Lockwood said.

Under the expanded program, TPWD has set an overall target of collecting tissue samples from 7,600 free-range whitetails. The state’s previous sampling regime for free-range whitetails produced a statistical confidence level of 95 percent based on a goal of determining if CWD was present in as few as 1 percent of the deer population. The new sampling program will provide a confidence level of 99 percent or higher, Lockwood said.

Those samples will come from hunters who voluntarily offer TPWD biologists the opportunity to remove tissue from the brain of whitetails the hunters take. The most reliable and, currently, only certified test for CWD, which evidence indicates is caused by a prion (abnormal protein) that triggers neurodegeneration resulting in progressive deterioration of the infected animal, involves testing tissue from the brain.

Coordination is key

Under the plan, hunters who want to participate in the program will be asked to coordinate tissue collection though TPWD wildlife division staff in the area they hunt. Ahead of this deer season, TPWD biologists in some areas of the state already have been working with landowners and deer hunters to arrange tissue collection from successful deer hunters, Lockwood said. In other areas, hunters wanting to participate will be asked to contact their local TPWD wildlife biologist; the agency’s website,, includes names and contact information of TPWD wildlife biologists, by county.

Also, Lockwood said, the agency plans to include on its website an icon hunters can click to see a schedule of when and were TPWD biologists will be stationed at local deer processing businesses or other public locations where hunters can bring their deer for tissue sample collection.

The agency plans to set up check stations in Hondo and Bandera, towns nearest the site of the Medina County deer breeding/production operation, where the first CWD-positive whitetail found in Texas was documented in June and three more deer subsequently were confirmed infected with the transmissible spongiform encephalopathy. Those two check stations will be staffed each day from mid-October through January, Lockwood said.

No cost to hunters

The sampling program is strictly voluntary, Lockwood said, and no fee will be charged hunters who offer their deer for sampling. Samples must be collected within 24 hours of the deer being taken, 48 hours if the carcass is kept refrigerated. In most cases, biologists will be able to relatively quickly remove the tissue and the hunter can take the entire animal. But in some cases, biologists will ask that the hunter allow them to retain the deer’s entire head. In those cases, the hunter will be given a document legally necessary as proof of the deer’s sex, required until the deer reached the hunter’s home or a deer processing business.

The hunter, who will be asked to provide contact information and location where the deer was taken, also will be given a receipt that includes an ID number for the sample. Samples will be sent to the Texas A&M Veterinary Diagnostic Lab and results, which could take three to four weeks to process, will be posted online where the hunter can access them.

Lockwood said he is optimistic the sampling will not find CWD-positive individuals in the state’s free-ranging whitetail herd – the nation’s largest at almost 4 million animals.

“I’m really hoping not to find it. I’m not expecting to find it in the free-ranging whitetail herd,” he said, adding the agency has developed response plans should a CWD-positive free-range whitetail be found.

Texas has some experience dealing with CWD. In 2012, CWD was detected in a free-ranging mule deer in the Hueco Mountains of far West Texas. That deer and eight subsequent CWD-positive mule deer found in the same area are believed to have contracted the disease from CWD-positive mule deer in southern New Mexico. TPWD and Texas Animal Health Commission response was to adopt regulations restricting movement of deer, elk, and other susceptible species within or from a “containment” zone around the isolated area, and enhance surveillance efforts.

Texas is one of 23 states and two Canadian provinces where chronic wasting disease has been found in either captive-held or free-range cervids such as whitetail, mule deer and elk.

The disease can take months or years to manifest, is progressive and in its later stages often results in significant loss of weight and body condition.

CWD has not proven transmissible to humans. But the World Health Organization and the U.S. Centers for Disease Control and Prevention recommend not consuming meat from infected animals.