Officials breakdown chronic wasting disease in Texas deer

A case of chronic wasting disease was detected in a deer in Val Verde County Dec. 19.

A case of chronic wasting disease was detected in a deer in Val Verde County Dec. 19, sparking containment strategies by the Texas Parks and Wildlife Department and Texas Animal Health Commission.

“Because eradication is thought to be impossible once CWD becomes established in a population, it is imperative that we work with other agencies, landowners and hunters to contain this disease within a limited geographic area and prevent it from spreading further among Texas deer populations,” TPWD’s Wildlife Veterinarian Dr. Bob Dittmar said. “This containment strategy is particularly urgent considering [Val Verde County] detection happened in the middle of general deer season.”

Parker County Ag Extension Agent Jay Kingston said chronic wasting disease has not been found in the county.

“CWD is a disease that affects the nervous system in white-tailed deer, mule deer, red deer, elk and moose. It is one in a group of diseases called the transmissible spongiform encephalopathies. It is caused by a misfolded protein, prions, which causes host animals to replicate the prions,” Kingston said. “Prions interrupt and degrade nerve cells and ultimately eliminate basic nervous system functions, leading to death. The good news is that CWD cannot be transmitted to humans or livestock. This disease is spread from direct and indirect contact with saliva, urine, feces or a carcass. Lateral transmission between two animals is the most common route of infection.”

According to the TPWD, symptoms of infected animals include emaciation, excessive salivation, lack of muscle coordination, difficulty swallowing, excessive thirst and excessive urination. Subtle behavioral changes like loss of fear of humans or other abnormal behavior are often the first signs noticed. Clinically-ill animals may have an exaggerated wide posture, may stagger and carry the head and ears lowered, dull expression and have a seemingly shaggy hair coat — these symptoms don’t occur until the terminal stages of the disease process.

“There has been no reported cases of chronic wasting disease in Parker County. The lead agencies would be Texas Parks and Wildlife Department and Texas Animal Health Commission. They have guidelines and action plans they would take to help minimize the spread of this disease,” Kingston said. “The successfulness of minimizing the effect would require the help of landowners.”

The disease is a major concern among the deer population, according to TPWD.

“Population impacts to our deer herds are a major concern. Several state agencies have documented population effects in some herds that have had CWD for a long time and the prevalence or number of animals infected is high,” according to the TPWD. “In those herds, population declines are occurring as well as shifts in age structure, to younger animals resulting in fewer mature animals. In addition, CWD infected deer in these populations are experiencing higher death losses compared to uninfected deer to due predation, car collision and more likely to be harvested by hunters. These impacts could affect hunting and processing deer.”

When taking deer to a game processor, hunters may consider requesting their animals be processed individually without meat from other animals being added to meat from their animal, according to the TPWD. Hunters should report any suspected cases of CWD to TPWD or TAHC immediately. Proper disposal of carcasses is strongly recommended for big game harvested in any area identified as a CWD endemic zone in order to minimize the risk of spreading CWD via infected carcass to other areas of the state.

Since it was first recognized in 1967 in Colorado, CWD has been documented in captive and free-ranging deer in 25 states. The first case in Texas was discovered in 2012 in free-ranging mule deer in the Hueco Mountains of West Texas. Since then, CWD has also been found in white-tailed deer and elk in Dallam County, Hartley County, Medina County, El Paso County, Uvalde County, Hudspeth County, Lavaca County and most recently, Val Verde County.

“Though CWD has not been discovered in exotic susceptible species in Val Verde County, our agency is working proactively alongside our TPWD partners to achieve enhanced surveillance for all susceptible species in the identified zones,” TAHC Executive Director and State Veterinarian Dr. Andy Schwartz said.

As Kingston said, the TPWD has found no evidence that CWD poses a serious risk to humans or domestic animals, but there is no treatment for animals with the disease.

“Keep in mind we are talking about wild populations of animals. There is no vaccine to prevent infection and once infected, there are no effective treatments. The best thing we can do now is to manage susceptible animal populations,” Kingston said. “This would include removing and properly disposing of potentially infected animals, preventing high densities of susceptible animals by continuing to hunt and harvest, and minimizing places where susceptible animals congregate, such as feeding stations.”

For more information and to monitor CWD, visit tpwd.texas.gov

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