Manitoba looking at next steps to curtail 'zombie deer' disease after case discovered near Winkler

A provincial biologist says he's optimistic that the so-called "zombie deer" disease can be contained in Manitoba, after only four positive cases of chronic wasting disease were found among the more than 4,000 deer samples analyzed during the 2023 hunting season.

But a recent case raises questions about just how prevalent the disease is in Manitoba.

Chronic wasting disease has been detected a total of 26 times in Manitoba since the first case here was discovered in 2021. The total includes 22 mule deer and four white-tailed deer, most of which were found in two distinct areas near the Saskatchewan border, the province says.

The disease is more common among mule deer than white-tails, and more common in males than females. But Manitoba's first white-tailed doe with the disease was recently confirmed near Winkler — a region of the province which had no known history of the disease, the province said in late January.

"It's sort of an anomaly for us," Richard Davis, manager of Manitoba's Wildlife Health Program, told Radio-Canada.

It would be "a long distance for white-tailed deer to move" from the western area where most other cases were found to Winkler, in south-central Manitoba, said Davis.

"It's not unheard of, but it's very odd.… For her to be infected sort of implies that there might be others out there that are infected in that area."

Davis says the province is on the right track to slow the spread of the disease.

However, "Whether or not it's become endemic, I'm not positive on that," he said, adding that the province will continue to "spot control" new cases.

'Our toolbox is not very full'

Chronic wasting disease can affect the brain and nervous system of members of the cervid, or deer, family, including white-tailed deer, mule deer, moose and elk. The disease is always fatal to those animals.

Late-stage symptoms leave the animals stumbling, unable to hold their heads up and salivating excessively, giving them an almost zombie-like appearance — which has led to chronic wasting disease sometimes being referred to as "zombie deer" disease.

Daniel Dupont, a biology instructor at St. Boniface University, says CWD is a strange disease.

"It's not a bacteria, it's not a virus," he said, but essentially a "malforming protein" that affects the nervous system.

"And essentially over time, an infected individual will become very weak, very skinny, and eventually will die."

Although there is no evidence of transmission of the disease to humans, Health Canada recommends not eating meat from an infected animal.

Davis said the province has taken baby steps toward managing the disease's spread, but "one of the big ones" was building up lab capacity for testing.

"We had the good fortune of partnering with the Public Health Agency of Canada at their National Microbiology Lab in Winnipeg," he said.

The province has adopted other measures to control the spread of the disease, such as allowing hunters to send in their own samples for testing and offering mule deer hunting licences for the first time in decades, said Davis.

Culls have been another tactic, since there is no established test for CWD among live deer, but it's something Davis says is "not very popular.… A lot of the land owners don't like doing that."

The province is still determining its response to the recently discovered doe, but "our toolbox is not very full," said Davis.

"The only option we have is a cull, but in this case, we're going to wait a little bit. We want to get some more information."

The province is also considering aerial surveys and looking at samples taken from areas around Winkler and in North Dakota, he said.

Public can aid prevention

St. Boniface University's Dupont says there's no win-win solution when it comes to CWD management.

"The reality is that no matter what you do, you're never going to please everybody, so if it's a cull, that is obviously quite controversial. Nobody wants to see deer in their backyard being removed," he said.

Trying to eradicate the disease from an area can be challenging, and it's become established in provinces like Alberta and Saskatchewan, said Dupont.

He suggests Manitoba learn from other places that have succeeded in eradicating CWD, as an endemic state could hurt populations of hooved animals, or ungulates.

"There could be implications for populations in terms of declines, and especially when we're talking about populations that are already under a certain amount of stress," he said.

"When you include a disease like CWD into the mix, that could really have an impact on the overall density and the overall health of ungulate populations within the province."

The public can play a role in controlling CWD's spread in Manitoba, Dupont says. People should avoid feeding wildlife and observe deer for anything unusual in order to curtail CWD in Manitoba.

"If anybody sees a kind of abnormally behaving deer, or deer that seem particularly skinny, I would suggest that they report it."