The Vermont Fish & Wildlife Board has voted to ban the possession and use by hunters of natural lures based on deer urine or other fluids beginning in 2016. By doing so the board hopes to reduce the threat of chronic wasting disease (CWD) entering the state, which has the potential to devastate Vermont’s deer herd. Deer urine lures are not tested for CWD, nor is it possible to track and recall bottles of lure that have been sold from a facility that later tests positive for the disease.
The disease is currently found in 23 states and two Canadian provinces.
CWD is 100 percent fatal in infected individuals, and infection levels can approach 50 percent in adult bucks. Deer may not show symptoms of the disease for several years after being infected. CWD can be spread in deer urine, feces and saliva, and can be deposited in soil, where it can remain infectious for decades. The form of the disease found in sheep has been infectious18 years after being deposited in soil, according to wildlife veterinarian Dr. Walter Cottrell.
Dr. Cottrell has worked closely with the Vermont Fish & Wildlife Department as a contract wildlife veterinarian since retirement as wildlife veterinarian for Pennsylvania. He presented on the science of CWD to the Fish & Wildlife Board at its April 22 meeting.
“Because of its long incubation period of months to years, when this disease arrives in a new place, it can potentially be there for a long time before it is detected,” said Dr. Cottrell. “And once the disease is there the genie is out of the bottle. Based on the experiences of the affected states and provinces, it never leaves.” Dr. Cottrell outlined how quickly the disease can spread among deer populations. In Wyoming, 12 percent of the mule deer population was infected in 1997; today, 47 percent of the population is infected.
According to Dr. Cottrell, there currently is no test for CWD on living animals–tests are performed on deer only after they die, since deer are able to contract CWD and spread the disease for up to a year and possibly longer before they demonstrate any clinical signs of the disease.
Captive deer populations have been implicated in the spread of CWD in several states. While many captive deer facilities claim that their facilities are “CWD-free,” urine lures from different sources are commonly mixed so hunters are unable to tell the origin of the product. The first case of CWD in Pennsylvania was recorded in a captive deer facility that was considered “CWD-free” and was selling deer urine lures online, according to a letter to the board from Dr. Krysten Schuler, a researcher the Cornell University College of Veterinary Medicine.
“Pennsylvania officials have been unable to trace the source of CWD in their captive cervid industry, nor has the source been determined for CWD-positive facilities detected in the last five years in Wisconsin, Minnesota, Missouri, Iowa, Utah, and Alberta, Canada,” said Dr. Schuler in a letter to Vermont Fish & Wildlife. “Once CWD is established in wild cervids, no state or province has been able to control or eliminate it despite monumental efforts and expense. Therefore, implementing strong preventative measures is the only tool available to combat this disease.”
Dr. Cottrell agreed, saying that banning natural deer urine lures is one of the few things the Board can do to prevent the spread of CWD into Vermont. Ontario, Arizona and some areas of Pennsylvania prohibit the use of such lures.
“The Fish & Wildlife Department fully supports the board in this important step to protect Vermont’s deer herd,” said Mark Scott, director of wildlife for the Vermont Fish & Wildlife Department. “This rule still allows hunters to use synthetic lures which pose no threat to the herd.”
Dr. Nancy Matthews performed research on CWD in Wisconsin for 13 years before stepping into the role of dean of UVM’s Rubenstein School of Environment and Natural Resources. In a letter to the Fish & Wildlife Board, Dr. Matthews also expressed her support for the science behind the ban.
“Based on my personal research and an understanding of the existing scientific literature, I fully endorse the proposed ban,” wrote Dr. Matthews. “Simply put, it is in the best interest of the deer and moose populations in the state.”
One more board vote will follow in the coming months. The proposed ban would become effective in 2016.