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10% of Estes Elk have chronic wasting disease |
10% of the Elk tested in RMNP had chronic wasting disease and were euthanized by the NPS.
By John Cordsen of the Estes Park Trail Gazette
And Press Reports
More than a dozen cow elk tagged in a Rocky Mountain National Park research project to develop a live test for chronic wasting disease (CWD) have tested positive for the fatal affliction. Elk were captured from early January through mid-March. The majority of captures took place in Moraine Park and near Beaver Meadows Visitor Center. Out of 136 female elk captured, (there were 117 usable biopsies), 13 tested CWD positive and were euthanized.
The results were garnered from a research project begun in January in the Park to evaluate procedures for testing live elk for CWD. The fieldwork furthered research in a live elk test for CWD and the effectiveness of a new experimental multi-year fertility control agent. The research was part of the Rocky Mountain National Park Elk and Vegetation Management Plan, which was released in early December 2007.
This 2008 research was the first time free ranging elk have been tested for CWD using this live procedure where rectal biopsies are taken.
An Elk which tested negative for living in Rocky Mountain National Park
Research initially called for 120 cow elk to be chosen at random. Researchers darted the animals with a potent narcotic type drug to put the animal down. Once the elk was down scientists blindfold the elk and collected saliva, hair, fecal and blood samples in addition to the birth control injections and rectal biopsies. Once the procedure was completed the animal was given a series of reversal drugs and released.
Researchers used the immuno-suppressant GonaCon, that was developed by the USDA in their "birth control studies". The drug is in its final steps of testing as it has already proven to be fairly successful in captive animals. The ongoing study in RMNP is the first time researchers have been able to test the drug in the wild. Results from the study will then be published and hopefully used in future wildlife management applications.
The rectal biopsies were sent in for testing. Animals testing positive were located and identified through collars that were placed on them during the initial capture process.
After the animal was destroyed complete necropsies were performed; these confirmed the live test results. Based on those results there was an 11 percent estimated CWD prevalence rate in this sample population. At the time of capture there was no obvious evidence of clinical CWD.
Researchers indicated they were not surprised at the results since previous research in the Park has shown that the elk herd in Rocky Mountain National Park and the Estes Valley is larger, less migratory and more concentrated than it would be under natural conditions. Research has also shown that elk densities on the core winter range are the highest concentrations ever documented for a free-ranging population in the Rocky Mountains.
Over the next several years, in conjunction with the proposed lethal reduction of elk, researchers will continue to conduct studies to evaluate procedures for testing live elk for CWD. Currently, there is a live CWD test effective for deer, but CWD diagnosis in live elk has received limited evaluation to date. Until now, the disease could only be reliably diagnosed after death in elk. Any elk which tests positive for CWD will be lethally removed from the population, thereby contributing to annual population reduction targets. These targets will be developed each year based on annual population surveys and hunter success outside the Park. Over the next three years elk population reduction will gradually remove study elk and the CWD status will be evaluated.
Chronic wasting disease was first reported in free-ranging wildlife in 1981. It is a member of the transmissible spongiform encephalopathy (TSE) disease family, which also includes bovine spongiform encephalopathy in cattle (BSE, also known as Mad Cow disease) and scrapie in domestic sheep and goats. CWD is fatal in deer and elk. Northeastern Colorado (including the eastside of Rocky Mountain National Park), southeastern Wyoming and western Nebraska are considered the endemic area for the disease.
Participants in the studies include scientists from the Colorado State University Department of Biomedical Sciences, the National Park Service, USDA National Wildlife Research Center, Colorado State University Department of Microbiology, Immunology and Pathology; USDA Agricultural Research Service. The Colorado Division of Wildlife is participating in the study on the live CWD test.
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