On May 18, Wisconsin Governor Scott McCallum signed a bill that gives wildlife officials broad powers to deal with an outbreak of chronic wasting disease in the state's deer population. As part of the $4 million plan, the Wisconsin Department of Natural Resources plans to kill every one of the estimated 15,000 deer in a 287-square-mile area, using whatever means necessary, including aerial shootings.
The plan is based entirely on the fact that Wisconsin officials found chronic wasting disease (CWD) in 14 deer in the southwestern part of the state.
Wisconsin's scorched-earth response to the CWD outbreak underscores the difficulty in dealing with this disease, which kills deer, elk and likely any other cervid species such as moose, caribou and key deer. Although it has not yet been shown to move naturally from cervid to human or cattle, CWD stirs up fears of Britain's mad cow disease, which forced the slaughter of millions of cattle and killed dozens of people; CWD also causes wildlife recreation industries to tremble in their hiking and hunting boots.
Because of these fears, citizens in states where CWD has been discovered in captive and wild populations of deer and elk—Wyoming, Montana, Colorado, Nebraska, New Mexico, South Dakota, Saskatchewan, and as far east as Wisconsin—clamor loudly for action. And that action has been, and likely will continue to be, state and federally funded killing campaigns like the one in Wisconsin.
But this deadly "solution" has a couple of problems: It is not likely to eradicate the disease from the infected area, and it does nothing to combat one of the main sources of CWD—game farms, which transport live deer and elk across state lines and threaten to spread CWD across the country.
The only thing mass slaughter campaigns can guarantee is that thousands of animals will die, including many healthy ones.
Chronic Wasting Disease
Chronic wasting disease is a transmissible spongiform encephalopathy (TSE) of deer and elk. Natural infections have occurred in mule deer, white-tailed deer, and Rocky Mountain elk, and the disease has been present in mule deer populations for at least 30 years.
CWD poses significant challenges for wildlife managers attempting to control or eradicate the disease. While modes of transmission of CWD remain a subject of ongoing research, strong evidence suggests that it can be spread by direct contact (from animal to animal). However, the disease agent appears to be highly resistant in the environment, potentially remaining viable for years; this has prompted concerns that the disease may be spread by indirect contact (e.g. contact with contaminated soil). Unnaturally large concentrations of deer or elk populations, such as those found in captive settings or with the supplemental feeding of wild cervids, can increase the likelihood of CWD transmission. Contaminated pastures are thought to have served as sources of infection in some CWD epidemics.
No treatment is available for animals infected with CWD. Once clinical signs develop, the disease is invariably fatal. Similarly, no vaccine is available to prevent CWD infection. In addition, long incubation periods, subtle early clinical signs, absence of live-animal diagnostic tests feasible for large numbers of free-ranging cervids, the persistent infectious-like protein, possible environmental contamination, and an incomplete understanding of the modes of transmission all constrain wildlife officials in controlling or eradicating CWD.
Current Management Plans: Help or Hindrance?
In captive facilities, the current management options are limited to quarantine or killing of CWD-affected herds. In the 1990s, two attempts to eradicate CWD from cervid research facilities failed; the causes of these failures were not determined, but residual environmental contamination was likely in both cases. Whether contaminated environments can ever be completely disinfected remains questionable.
Managing CWD in free-ranging animals presents an even bigger challenge. Programs established to date focus on containing CWD or reducing the disease in localized areas. Some states have banned the relocation of cervids and the maintenance of feeding stations. Colorado even slaughtered cervids in an area with high CWD prevalence, but the effectiveness of that approach remains to be determined.
Slaughter programs may seem logical, given that they reduce population densities and therefore the opportunities for transmission and translocation. But the migration patterns and social behaviors of some deer and elk (e.g. dispersal of yearling bucks) may allow the continued spread of the disease. In addition, many deer and elk are likely to escape the heavily hunted area and enter a new territory with no previous occurrence of CWD.
The slaughter campaigns may also create unintentional orphans, because does killed at this time of year will be nursing fawns that are hidden away. When mothers are killed, the fawns will die from starvation.
Alternatives and Prevention
Population ecologist Dr. Charles Southwick of the University of Colorado believes there is an alternative to mass slaughter, one that will avoid killing thousands of otherwise healthy animals. He advises capturing deer and taking biopsies of tonsil tissue, where evidence of infection may appear before symptoms develop, at least in mule deer. If this live-animal test were found to be effective for other cervid species, it would help to avoid destroying healthy animals.
Wildlife disease experts are divided on the feasibility of the current live-animal test for large numbers of free-ranging cervids over large areas. However, at a minimum, this live-animal test could be incorporated into a non-lethal CWD surveillance plan to monitor the prevalence of the disease.
Prevention is another logical option. To understand how prevention can help alleviate CWD, you need to understand how game farms contribute to the spread of the disease.
Game ranching has grown dramatically during the last decade, principally as an alternative animal husbandry industry. States such as Michigan, Minnesota, Pennsylvania, and Wisconsin have hundreds of game farms, where revenue is generated through the sale of animal parts and, in many states, through canned hunts. Animals are routinely imported to "stock" these game farms. Wisconsin, ironically enough, has more game farms than any other state—947 of them, with 35,000 animals raised for meat, velvet and hunting.
Scientists such as Dr. Valerius Geist of the University of Calgary have warned people for years about the threats that game farms pose to wildlife. To Geist, game farms represent the unbridled commercialization of wildlife, which runs against the norms that have dominated U.S. wildlife policy since the early 20th century. They also pose disease threats to wildlife and the livestock industry, and contribute to the abuse of animals.
Scientists have identified a number of core hot spots—in Wyoming, Colorado and Nebraska—from which they think CWD has spread. The common belief is that cervids transported from a hot spot help spread the disease to new areas. CWD has now been found in captive cervids in Kansas, Montana, Oklahoma, Saskatchewan, and South Dakota. Game farms, of course, are one of the main importers of cervids.
Some states such as Colorado, Connecticut, Indiana, Nebraska, New York, North Carolina, Texas, Virginia and Wisconsin have recently enacted a moratorium on the importation of some or all cervids. Eight other states have limited imports by banning canned hunts completely.
In Montana, where the state failed to address the emerging CWD problem, the people (mainly hunters) took matters into their own hands by passing a ballot initiative in November 2000 to ban canned hunts and to halt the establishment of any new game farming operations. A number of other states, such as Wyoming, have persistently resisted the efforts of the game farm industry to gain a foothold.
States have little to gain, and much to lose, by encouraging game farming. The industry claims to generate millions, but its operations have also contributed to disease threats that cost states millions of dollars. What's more, the spread of CWD threatens industries that generate revenues that dwarf those produced by game ranches, notably the wildlife watching and hunting industries.
A columnist with the Denver Post noted, "Colorado's 160 domestic elk and deer ranches are, at most, a $44 million a year industry. So to coddle a $44 million specialty business, legislators potentially jeopardized two economic engines worth more than $5 billion to Colorado. What business book did these guys read?"
HSUS Recommendations
- Stop the mass slaughter campaigns, which are not justified to manage the spread of chronic wasting disease. There is a lack of scientific evidence to support the effectiveness of this method. In fact, the slaughter of thousands of healthy animals may only help spread the disease.
- States should not allow game farms to operate within their borders. There is little economic incentive, and, just the opposite, these game farms could cost the state and federal governments hundreds of millions of dollars to contain the disease, to compensate game farm operators, and to depopulate wild and captive herds.
- The focus should be on prevention. We call for a nation-wide moratorium on the importation and interstate transport of cervids and other exotic animals, at least until effective control measures, such as reliable ante-mortem diagnostic tests and effective vaccinations, can be developed.
- We urge the passage of H.R. 3464 and S. 1655, the Captive Exotic Animal Protection Act, introduced by Rep. Sam Farr (D-CA) and Senator Joe Biden (D-DE) respectively, which would ban the transport of captive exotics for the purpose of canned hunts.
- Further research is desperately needed to improve our understanding of the modes of CWD transmission and potential genetic resistance to the disease. More research is also needed to further develop live-animal tests.
- Finally, we need better monitoring of the international and interstate trade in wildlife. Ranched cervids include both native and exotic species, and scientists believe it is likely that many species of the cervid family are susceptible to CWD. Unfortunately, the oversight of exotic mammals falls outside of the traditional jurisdiction of state agriculture departments and fish and game agencies. In short, these animals often fall into regulatory limbo at the state level. It is important to monitor the transport of all species and subspecies of animals that are potential hosts of the disease.
What You Can Do
- Write to your U.S. Representative and Senators and tell them to support the Captive Exotic Animal Protection Act (H.R. 3464 in the House and S. 1655 in the Senate).
- If you live in Iowa, Minnesota, or Pennsylvania, tell your state legislators to oppose the cervid hunting legislation before them. In Iowa the bill is S.F. 335; in Minnesota the bills are H.F. 747 and S.F. 1046; and in Pennsylvania the bill is S.B. 1158.
