It’s estimated 40 percent of wild deer in the South Saskatchewan River Valley are infected with chronic wasting disease
Chronic wasting disease is becoming more common across all parts of Saskatchewan and is now considered endemic in certain areas of the province.
In a presentation to the Saskatchewan Association of Rural Municipalities convention held last week in Saskatoon, Iga Stasiak, a wildlife health specialist with the Saskatchewan environment ministry, said 349 cases of CWD were confirmed through the province’s voluntary CWD testing program last year.
Before last year, roughly 450 cases of the disease were documented in Saskatchewan over a 20-year period.
The disease is most prevalent in the Lloydminster area, the Love-Nipawin region of northeastern Saskatchewan and in parts of the South Saskatchewan River Valley, where infection rates among the wild deer population are estimated at around 40 percent.
“There are concerns related to the spread of the disease across the province,” Stasiak said.
“This year, we had positive detections for the first time … in south-central and eastern Saskatchewan. However, infection levels in these areas are still significantly lower than our endemic or core areas.”
CWD is a brain-wasting disease that affects wild and farmed cervid species, including deer, elk and moose.
Saskatchewan’s voluntary CWD testing program encourages hunters to submit the heads of bagged animals for free testing.
However, resources available to the provincial testing program are being stretched to the limit as concerns about the disease continue to grow and the number of voluntary submissions continues to rise.
The provincial testing program received more than 2,000 submissions last year, up from 850 in 2017.
“We have a limited budget for surveillance, and there are a lot more hunters that are getting their animals tested because of food safety concerns,” Stasiak said.
“The program was always intended as a wildlife health monitoring program, not as a food safety program, and for that reason, resources are really being stretched.”
Stasiak said concerns about the disease are growing as the number of positive tests continues to increase and infected animals continue to show up in new areas of the province.
In 2018, the provincial test program had positive detections in 10 additional wildlife management zones.
For hunters, disposal of infected carcasses is a growing concern.
Regional landfills do not accept carcasses or animal parts, so many hunters are left to their own devices when deciding what to do with infected carcasses.
Earlier this year, a food bank in Prince Albert, Sask., turned away donations of wild game meat, citing concerns over the distribution of meat that could potentially be infected with CWD.
Stasiak said there is no research to indicate that consumption of meat from a CWD-infected animal has any negative impact on human health.
But as a precaution, the province still recommends that hunters avoid eating meat from an animal that’s known to be infected.
“That is still the recommendation,” Stasiak said.
“Ultimately it’s up to the hunter to decide … if they’re willing to take that risk.”
The spread of CWD also has implications for the province’s agricultural sector.
In April 2018, Ottawa made changes to the federal CWD control program.
Those changes ended indemnification and depopulation services for game farms that test positive for the disease but are not enrolled in the Canadian Food Inspection Agency’s voluntary herd certification program.
The CFIA herd certification program was designed to help game farms distinguish themselves as CWD-free operations for marketing and trade purposes.
Out of an estimated 185 game farms in Saskatchewan, roughly 15 percent are believed to be enrolled in the program.
“Unfortunately, the majority of producers in Saskatchewan are not enrolled,” Stasiak said.
That means that as of April 2018, they are no longer eligible for indemnification or depopulation if they have a positive.
Some SARM delegates at last week’s convention raised concerns about the spread of the disease and its potential transmission to other species, including cattle.
CWD is spread through the urine, feces and saliva of infected animals. There is also evidence that prions associated with the disease can survive in certain soil types.
However, Stasiak said CWD has a strong inter-species barrier, meaning it’s unlikely to affect non-cervid species.
“There is still a lot that’s not known about potential transmission to other species,” Stasiak said.
“There was one study that demonstrated transmission to pigs, which raises some concerns about the role of wild boars as potential reservoirs of infection in a highly contaminated landscape.
“But there have been no studies that demonstrated transmission to cattle, and there has been a fair amount of research in this area.”