Posted 1:20 am Thursday, July 12, 2012
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Chronic Wasting Disease Finally Located In Texas
By STEVE KNIGHT
Outdoors Editor
After 12 years and testing almost 35,000 wild and pen-reared deer, Chronic Wasting Disease has finally been detected in Texas.
Texas Parks and Wildlife Department and Texas Animal Health Commission officials announced Tuesday that tests had come back positive on a pair of mule deer found on a 150,000 acre sample area in the Hueco Mountains in far West Texas.
The deer were the only two infected out of 31 tested in what is considered a travel corridor south of where the disease was discovered in mule deer in New Mexico last winter.
“This is definitely not a crisis,” said Clayton Wolf, TPWD’s Wildlife Division director. “We need to move forward in a prudent manner. We are not going to overreact like some states have, but we will move forward.”
Outdoors Editor
After 12 years and testing almost 35,000 wild and pen-reared deer, Chronic Wasting Disease has finally been detected in Texas.
Texas Parks and Wildlife Department and Texas Animal Health Commission officials announced Tuesday that tests had come back positive on a pair of mule deer found on a 150,000 acre sample area in the Hueco Mountains in far West Texas.
The deer were the only two infected out of 31 tested in what is considered a travel corridor south of where the disease was discovered in mule deer in New Mexico last winter.
“This is definitely not a crisis,” said Clayton Wolf, TPWD’s Wildlife Division director. “We need to move forward in a prudent manner. We are not going to overreact like some states have, but we will move forward.”
The state has been on the lookout for CWD since 2002. Not believed to be dangerous to humans, the disease is deadly to members of the deer family that also includes white-tailed deer, elk, sika and red deer.
It was first discovered in a captive deer herd in Colorado in 1967, and has now been detected in 19 other states and two Canadian provinces.
Wolf said based on a plan devised by a Texas task force, the mule deer samples were collected on private ranches. The plan was put into action after New Mexico alerted Texas officials that CWD had been found in deer near the two states’ border.
“All the deer we collected were in decent shape. I would not say any that we collected had clinical signs of the disease,” said Shawn Gray, TPWD’s mule deer program leader.
Clinical signs of the disease include weight loss, listlessness, lowering of the head and repetitive walking in set patterns.
The area where the testing was conducted has a low mule deer density of about two per 640 acres.
Gray said deer numbers haven’t dropped drastically, an indication that the disease may not be widespread. A lingering drought is having a bigger impact on the population.
TPWD plans to shut down man-made deer movement in the detected zone and a high-risk zone just beyond. It is expected that the Parks and Wildlife Commission will approve the plan that will basically halt any permitted deer movement in the two zone at its August meeting, There are currently no permits approved for trapping mule deer in the area. Texas Animal Health Commission has already moved towards doing the same with non-game deer species including elk, red deer and sika deer.
TPWD is also expected to set up mandatory hunter check stations within the detected zone and voluntary check stations in the high-risk zone this fall in an effort to collect more samples for testing.
Wolf said the disease is a slowly progressive disease, and that it could take decades for the prevalence rate to go up.
“Incubation time from when exposure happens until a deer shows clinical signs can be within a month and 59 months, that is the longest I have ever seen,” said Dr. Andy Schwartz, Texas Animal Health Commission’s assistant executive director. He noted the timeframe for spreading the disease is relatively short and toward the end of the infected deer’s life after it starts showing signs of the disease.
CWD can be spread from animal to animal, from ground infected by the carcass of a diseased animal or from contaminated food or water sources.
“It can stay active in the soil for at least a year, but I don’t think we know the end (time span) for sure. If it is like other diseases it depends on environmental conditions. We are not dealing with an organism here. This is a piece of protein,” Schwartz said.
While the two infected deer were found within close proximity of each other, the experts believe the low deer density in the area may help prevent the spread of the disease.
Identifying CWD continues to require a dead animal test. New Mexico has worked with a live animal test using samples from a deer’s tonsil, but it is not approved and there have been some problems.
“There is a long incubation period, and although a test may come back clean it may be infected,” Schwartz said. New Mexico had such a situation where several tested deer did turn out to be positive, but had already been released. State officials have had to go back and look for the deer that had been fitted with collars before being released.
Texas is not expected to react to the discovery of CWD in extreme fashion as was the case in Wisconsin where state game officials recommended total depopulation of deer in portions of the state where it was discovered.
There is still a lot unknown about Chronic Wasting Disease, beginning with whether it has been around forever or is a recent disease. The fact it was eventually found in Texas is no surprise. It has probably surprised some, however, that the first evidence of CWD came in a remote population in the Trans Pecos region and not in a breeder pen elsewhere in the state.
Have a comment or opinion on this story? Contact outdoor writer Steve Knight by email at outdoor@tylerpaper.com.
Follow Steve Knight on Facebook at TylerPaper Outdoors and on Twitter @tyleroutdoor.
It was first discovered in a captive deer herd in Colorado in 1967, and has now been detected in 19 other states and two Canadian provinces.
Wolf said based on a plan devised by a Texas task force, the mule deer samples were collected on private ranches. The plan was put into action after New Mexico alerted Texas officials that CWD had been found in deer near the two states’ border.
“All the deer we collected were in decent shape. I would not say any that we collected had clinical signs of the disease,” said Shawn Gray, TPWD’s mule deer program leader.
Clinical signs of the disease include weight loss, listlessness, lowering of the head and repetitive walking in set patterns.
The area where the testing was conducted has a low mule deer density of about two per 640 acres.
Gray said deer numbers haven’t dropped drastically, an indication that the disease may not be widespread. A lingering drought is having a bigger impact on the population.
TPWD plans to shut down man-made deer movement in the detected zone and a high-risk zone just beyond. It is expected that the Parks and Wildlife Commission will approve the plan that will basically halt any permitted deer movement in the two zone at its August meeting, There are currently no permits approved for trapping mule deer in the area. Texas Animal Health Commission has already moved towards doing the same with non-game deer species including elk, red deer and sika deer.
TPWD is also expected to set up mandatory hunter check stations within the detected zone and voluntary check stations in the high-risk zone this fall in an effort to collect more samples for testing.
Wolf said the disease is a slowly progressive disease, and that it could take decades for the prevalence rate to go up.
“Incubation time from when exposure happens until a deer shows clinical signs can be within a month and 59 months, that is the longest I have ever seen,” said Dr. Andy Schwartz, Texas Animal Health Commission’s assistant executive director. He noted the timeframe for spreading the disease is relatively short and toward the end of the infected deer’s life after it starts showing signs of the disease.
CWD can be spread from animal to animal, from ground infected by the carcass of a diseased animal or from contaminated food or water sources.
“It can stay active in the soil for at least a year, but I don’t think we know the end (time span) for sure. If it is like other diseases it depends on environmental conditions. We are not dealing with an organism here. This is a piece of protein,” Schwartz said.
While the two infected deer were found within close proximity of each other, the experts believe the low deer density in the area may help prevent the spread of the disease.
Identifying CWD continues to require a dead animal test. New Mexico has worked with a live animal test using samples from a deer’s tonsil, but it is not approved and there have been some problems.
“There is a long incubation period, and although a test may come back clean it may be infected,” Schwartz said. New Mexico had such a situation where several tested deer did turn out to be positive, but had already been released. State officials have had to go back and look for the deer that had been fitted with collars before being released.
Texas is not expected to react to the discovery of CWD in extreme fashion as was the case in Wisconsin where state game officials recommended total depopulation of deer in portions of the state where it was discovered.
There is still a lot unknown about Chronic Wasting Disease, beginning with whether it has been around forever or is a recent disease. The fact it was eventually found in Texas is no surprise. It has probably surprised some, however, that the first evidence of CWD came in a remote population in the Trans Pecos region and not in a breeder pen elsewhere in the state.
Have a comment or opinion on this story? Contact outdoor writer Steve Knight by email at outdoor@tylerpaper.com.
Follow Steve Knight on Facebook at TylerPaper Outdoors and on Twitter @tyleroutdoor.
