Pennsylvania Game News - November 2010 - 12

this how prions crossed the Mississippi? The recently updated CWD Parts Ban is in the Pennsylvania Hunting and Trapping Digest (page 49) and at www.pgc.state.pa.us, under “Wildlife” and then “Wildlife Diseases.” Use of urine-based lures. This is a new risk factor, now that we know urine can contain infectious prions. These products are all created from captive cervid urine and travel freely across state lines; there is no regulation of that industry, nor is there a good understanding of the CWD status of herds producing the urine. In 2006 only two percent of captive cervid operations in Pennsylvania reported collecting and selling urine for lures. So where is the rest of what is on the shelf or sold by mail order coming from? We just don’t know. Can we say what the risk is? No, but it is not zero. Remember the facts about prions, soil binding and environmental persistence. Much emphasis has been placed on risk factors associated with captive cervids. This is largely because of a combination of the facts, including that there is such a long incubation period, there is no test for the disease for live animals, and because there is so much variation in the way the movements of these animals are regulated. There is also a clear epidemiological link between national and international movements of captive animals and subsequent movements of the disease. Pennsylvania ranks second only to Texas in number of captive cervids. There are between 1,100 and 1,200 businesses, with more than 23,000 captive cervids in the commonwealth. In those fenced settings we also worry about timely reporting of cervids that escape, nose-to-nose contact between wild and captive cervids, reporting and testing of sick and dead ani12

mals, and unknown movements of potentially infected animals between farms and shooting facilities. CWD risks related to establishment and amplification of the disease are: High deer densities, which facilitate the spread of the disease. We know we have large numbers of deer, especially in some locations. Feeding and baiting, which concentrate susceptible animals, result in greater likelihood of exposer to prions from infected cervids and an increased probability of environmental contamination. Conditions that lead to the introduction of the prions are more likely to lead to exposure to susceptible animals. Large populations of susceptible animals make the impact more profound. And factors that cause animals to congregate and facilitate the spread of the agent either directly, or indirectly through environmental contamination, are more likely to lead to the permanent establishment of the disease in a population. Should CWD become established in Pennsylvania it will change our deer and elk herds, possibly forever. It will also change things in the Game Commission and the Department of Agriculture. Responding to the introduction of this disease in Pennsylvania will almost certainly divert some resources from other programs. All of these are factors that make the disease hard to contain. In the history of this disease so far it has never been eliminated (except possibly in New York), or even slowed in its spread. Where it has been present the longest it has been shown to shorten the average lifespan of animals and cause the studied population to decline. It’s been said that CWD will come to us either by walking across our border or in a truck, meaning either from a dispersing wild cervid or a captive one imported here, or from cervid parts brought in by individuals hunting in CWD infected areas.
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Pennsylvania Game News - November 2010

Table of Contents for the Digital Edition of Pennsylvania Game News - November 2010