Wolves, Chronic Wasting Disease and Covid

Mule deer in Wyoming. Photo George Würthner

Recently, the Wyoming Game and Fish reported that between 2016 and 2020, Chronic Wasting Disease (CWD) was found in over 60% of mule deer tested in central Wyoming. Recent tests suggest it can reach 78% of all deer tested. A map shows the onset of the disease in Wyoming.

CWD is a fatal disease that can affect all members of the deer family, including deer, elk and moose.

There is a similar prion disease that infects humans called Cruetzfeldt-Jakob disease. It’s also deadly. These prion diseases cause tissue and neurological systems to degenerate, leaving the brain with sponge-like holes, among other fatal problems.

Some scientists believe that consuming animals infected with CWD could cross the species barrier and infect humans.

An experiment conducted by the Canadian Food Inspection Agency resulted in the transmission of CWD from the meat of cervids (moose, deer and elk) to macaque monkeys. The monkeys were infected by injection into the brain, and the animals were given CWD infected muscles.

This potential risk to human health has led to messages warning the fisheries and game departments not to eat infected animals. CWD has been found in 26 states and 3 Canadian provinces, including the Rocky Mountain states of Montana, Wyoming, Colorado, and recently Idaho.

Hunters are warned against ingestion or even contact with the blood and other fluids of infected animals. Photo George Würthner

There is also some evidence that transmission could occur through casual contact with the blood or fluids of an infected animal, which means, at the very least, that hunters should wear gloves when slaughtering an animal. animal.

The World Health Organization warns against feeding infected animals to other animals. He warns: “no tissue likely to contain BSE [Bovine Spongiform Encephalopathy] agent, part or product of an animal that has shown signs of TSE [Transmissible Spongiform Encephalopathy] should enter the food chain (human or animal).

CWD has a long latency period like Mad Cow Disease which is closely related to it. In other words, long before a deer or elk appear sick, they can get sick. Unfortunately, this means that there is no way for a hunter to know if the creature he has slaughtered has the disease until the animal is tested.

Infected herds have few older animals. Photo George Würthner

Evidence of the prevalence of the disease in a population is that there are few “old” animals. In heavily infected deer herds, few animals survive beyond 4 to 5 years before succumbing to the disease. As a result, in some states, a control mechanism has increased the hunting of all deer.

Most hunters seem ready to kill and often consume potentially infected animals despite these warnings.

Although CWD is spread from animal to animal, the prevailing idea is that prions remain in the soil or on plants eaten by healthy animals, which then contract the disease. Overcrowded herds are more susceptible to infection.

Wyoming operates state feeding areas that concentrate elk facilitating transmission of CWD. Photo George Würthner

This raises the issue in Wyoming, where the state operates 22 elk feeding stations to provide winter fodder. In such concentrated feeding operations, it is suspected that disease transmission is facilitated. For this reason, environmentalists have attempted to shut down foraging areas, especially on national forest lands.

Despite CWD’s danger to Wyoming’s deer and elk herds, the state has resisted dismantling feeding grounds. The reasons are very similar to the opposition to wearing masks and vaccines to reduce the spread of Covid.

Many Wyoming residents believe the threat of CWD transmission to humans is negligible. Additionally, many outfitters and hunters want the state to maintain high elk numbers for obvious reasons. While ranchers believe the foraging areas help prevent elk from moving to private land in the winter.

Fishing and hunting agencies are reluctant to minimize the risk of CWD transmission to humans as most of their income comes from the sale of hunting licenses and tags.

Wolves can spot a sick deer or moose before human hunters. Photo George Würthner

This brings me to the wolves. Wolves can spot a sick deer or elk long before it is obvious to human hunters. Some models suggest that wolves could reduce CWD to almost undetectable levels.

Yet Wyoming, like Idaho and Montana, has embarked on a wolf culling program that could effectively reduce the numbers of wolves to the point where they offer no control over the spread of CWD.

In essence, wolves are like masks and vaccines for the spread of Covid. They will not eliminate CWD, but they could help control its spread. Like vaccines, the goal is not to eradicate Covid but to reduce its incidence to the point where few deer, elk or other wildlife are infected. Wolves may be the “vaccine” needed to limit cervid encephalopathy.

Unsurprisingly, Wyoming is also a state whose human population largely rejects wearing masks, and many are opposed to vaccines. As a result, Wyoming is dead last in the percentage of its population that has been vaccinated against Covid. Only 47% of Wyoming residents are vaccinated compared to Vermont, where 77% have been vaccinated.

Despite good evidence that wolves could help protect Wyoming’s game populations, there is resistance to science and suspicion of government authority.

Elk carcass killed by wolves. CWD can drastically reduce both prey and therefore animals, including scavengers that relied on the slaughter of wolves. Photo George Würthner

The long-term implications of CWD on the evolutionary trajectory of herd populations and age structure are still unknown. For example, in uninfected populations, the older and more mature males perform the majority of reproduction, and often older females hold the “cultural” knowledge of migration routes, calving grounds and breeding grounds. wintering areas. However, in CWD herds with a high incidence of infection, there are few “old” individuals.

The implications of CWD-induced deer and elk population declines for other wildlife, including predators like wolves, cougars and bears, much less scavengers also need to be considered. If there was a significant reduction in the elk and deer herds, the ability to support these animals would be threatened.

Colorado has had the longest documented evidence of CWD infections, and some herds have an infection rate over 20%. But, so far, this has not led to the total collapse of Colorado ungulate populations.

Rather than culling wolves, states should promote wolves as a natural and effective agent that can reduce the incidence of CWD in ungulate populations. Photo George Würthner

Nonetheless, promoting wolves instead of slaughtering them might be the best antidote to the spread of CWD. But like vaccines and wearing masks, misinformation and prejudice can ultimately lead to lost hunting opportunities as well as declining wildlife populations.

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