Chronic wasting disease is spreading. Is Ontario ready?

The fatal brain disease has been infecting deer across North America. speaks with Keith Munro, wildlife biologist for Ontario Federation of Anglers and Hunters, about what it is and how to fight it 
By David Rockne Corrigan - Published on Jul 26, 2019
Last September, a case of chronic wasting disease, which affects deer, was found on a Quebec farm just 15 kilometres from the Ontario border. (Richard Buchan/CP)



An infectious disease that threatens wildlife is spreading quickly across North America — and Ontario has started to prepare for its arrival.

Wildlife biologists, economists, doctors, and hunters are calling for Canadian governments to take urgent preventative action against chronic wasting disease, a fatal brain disease that affects members of the deer family. Ontario is on watch: last September, a case was found on a farm in Grenville-sur-la-Rouge, Quebec, just 15 kilometres from the Ontario border. To date, the disease has also been found in Alberta and Saskatchewan, as well as in 26 U.S. states.

Last month, 30 experts, including scientists, economists, and Indigenous leaders, sent a letter to the prime minister in which they urged the federal government to “mandate, fund, and undertake emergency directives” to contain the disease, prevent human exposure, and expand the CWD surveillance program. They noted that a single case of bovine spongiform encephalopathy (“mad cow”) found in Alberta in 2003 triggered trade restrictions that led to billions in losses for cattle producers. CWD, they wrote, is a “vastly larger epidemic” and “far more virulent” than BSE. While the latter is transmitted through feed, CWD can be passed between live animals and from soil and plants, making it far more difficult to contain.    

Governments around the world are already taking action to limit its spread. For example, in October 2018, Norway cut off all imports of straw and hay from states or provinces where CWD had been discovered. During its own epidemic in 2017, Norway had to cull 6 per cent of its wild reindeer population, putting down more than 2,000 animals. 

As the disease creeps closer, the Ontario government is updating its CWD surveillance and response plan, first developed in 2005, in an attempt to minimize the threat and protect the recreational deer-hunting industry ­— a $275 million business in 2017.

The plan aims to prevent CWD and to protect the “socio-economic, cultural, and ecological benefits provided by Ontario’s wild deer, moose, elk, and caribou.” The government hopes that increased public awareness of the disease — and of its effects — will help keep the epidemic at bay. It also plans to take proactive measures, launching a public-awareness campaign and broadening restrictions on the import of high-risk deer parts, for example, and is preparing rapid-response strategies, including possible hunting-season closures and quarantine zones, that can be implemented if the disease is detected.

The Ontario Federation of Anglers and Hunters, which represents more than 100,000 members, recently endorsed the province’s approach. spoke with Keith Munro, OFAH’s wildlife biologist, about the symptoms of the disease and possible strategies to contain it. 

First off: What, exactly, is chronic wasting disease?

Chronic wasting disease is caused by an agent known as a prion. A prion is a misfolded protein. What happens is, when a deer encounters a CWD prion and takes it in — either from another deer or from the environment — it can cause the deer’s own proteins to misfold themselves. And then they accumulate into what are known as plaques, which then basically destroy brain tissue. The challenge is, these prions are not alive, so you can't kill them. And, so, say I go to Saskatchewan, and I harvest a deer. And I bring the whole thing back, and I butcher it, and I take the parts that I wasn't going to use — like the spine or the brain — and I just dispose of them in the woods. That could create a super-site of prions that other animals can come and get infected from. And that can persist for years. While we don’t yet have an example of hunters spreading the disease, it definitely needs to be avoided. Because of that, our hunter regulations focus on what parts and animal parts a hunter can bring back into the province.

How seriously is the OFAH taking this issue?

It's hugely important. The OFAH has an annual conference, which, in the past, has always been focused on general fish and wildlife topics. But, this year, we did it 100 per cent on CWD. We brought in experts from across the country and from the United States and did two pretty intense days on what CWD is, how you prevent its spread, how you manage it if you find it, and how to plot a path forward. And we didn’t have just the hunting community there: we also had people from tourism, different levels of government, public health, Indigenous communities — really everyone who can be affected. It's an issue that anyone who values healthy wildlife should be engaged in.

So this doesn’t just affect hunters?

CWD gets thought of as a very specific deer-related issue, and, usually, a hunter-related issue. It's really not. CWD is extremely harmful not just for white-tailed deer, but also for moose, elk, caribou. It has been demonstrated to cause population declines. It’s bad for people. There are potential health concerns around it. As of right now, the Centers for Disease Control and Prevention, in the U.S., recommends against eating meat from any CWD-positive animal. 

How has Ontario been able to keep it at bay for so long?

We’ve been pretty lucky, if I’m being honest. We’ve been shielded by our neighbours. Manitoba has done an excellent job of keeping it out of their province, which has really helped us. Also, New York State is the only jurisdiction that actually eradicated CWD. They had an outbreak in 2005 but had a very fast, aggressive, and effective response to the disease and were actually able to get rid of it, which is the only jurisdiction to have done that. Now it is in Minnesota and in Michigan. And then we had those cases on the Quebec deer farm, which is 15 kilometres from the eastern Ontario border. So it's definitely a lot closer. But, up until now, we have had those buffers.

How can hunters (and others) tell whether an animal has CWD?

One important point to make is that symptoms usually don't manifest until the late stages of the disease. So you can have an animal that looks completely healthy, but it's actually highly infected and highly infectious. And the real challenge there is that the only reliable way to tell if an animal is infected with CWD is to take samples from the brain. But the symptoms that you do tend to see, one of them is dramatic weight loss. That's where the “wasting” comes from. Stumbling, a lack of coordination, listlessness, a drooping of the head or ears — these are all things to look for.

The biggest thing is that there are very specific rules for hunters designed to prevent the spread of CWD. And those mostly relate to people who are going to hunt outside of the province and bring parts of deer back. Our hunter regulations focus on what deer parts a hunter can bring back into the province. It’s a little bit complicated, so I always refer hunters to just review the regulations themselves.

What do you think of the government's proposed plans?

Essentially, we support the plan, and we recommend that it's adopted immediately. It fixes a lot of potential pathways for CWD to get into the province. We just submitted our response to the plan [the deadline for comment was July 25 at 11:59 p.m.]. The biggest thing that comes up again and again in our response is that the plan is very in-depth about what MNRF would do. But it's not as clear what the Ministry of Agriculture, Food and Rural Affairs, for example, would do. And their role is very important, because they have the responsibility for deer farms, and deer farms have been linked to much of the spread of CWD in North America. Other ministries and agencies will be affected, too. If CWD is found in a provincial park, or if it gets into the caribou population, that would be the Ministry of Environment, Conservation and Parks. One of the challenges of CWD is that it overlaps with so many ministries and so many levels of government. The plan, in our view, lays out what is happening with MNRF — which makes sense since it is an MNRF document —  but we would like to see more detail on the actions that would be taken by other ministries, specifically OMAFRA.

This is one in a series of stories about issues affecting eastern Ontario. It's brought to you with the assistance of Queen’s University.

Ontario Hubs are made possible by the Barry and Laurie Green Family Charitable Trust & Goldie Feldman.​​​​​​​

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