Grasslands National Park prairie dog dies of sylvatic plague
A prairie dog at Grasslands National Park in 2005. Parks Canada advised the public on Friday, Aug. 13, 2010, of a single prairie dog mortality in Grasslands National Park, which has been confirmed as being as a result of sylvatic plague, a rare but naturally occurring disease in native wildlife.
Photograph by: Don Healy, Leader-Post files
REGINA — A black-tailed prairie dog in Grasslands National Park has died of plague, a rare but naturally occurring disease affecting ground squirrels throughout the southern prairies, Parks Canada said Friday.
Transmission of plague to people is possible through bites from infected fleas, but the risk to human health is described as very low.
Pat Fargey, a species-at-risk-specialist at Grasslands, said a researcher found a prairie dog carcass earlier this summer and it was sent to Saskatoon for testing, which is routine when there isn’t an obvious cause of death. The results indicating plague are unusual and sound dramatic, but wildlife disease specialists know the disease persists in the environment, Fargey said.
“We can detect antibodies to the disease in carnivores like coyotes,” he said. “If you collect blood from a coyote, you can tell whether it’s dined on an infected rodent because you can find antibodies to the bacterium in its blood.”
Like the black-tailed prairie dog, black-footed ferrets are also susceptible to plague — referred to as sylvatic plague — but the ferrets recently reintroduced to Grasslands were vaccinated, Fargey said.
The plague is an infectious disease caused by a bacterium called Yersinia pestis that can affect both animals and humans, according to the Public Health Agency of Canada. The agency notes on its website that the most widely known plague in human history is likely the “Black Death” bubonic plague of 14th century Europe, although outbreaks of plague are a rare occurrence today.
The last confirmed case of a human plague infection in Canada was in 1939, and it was non-fatal.
As a precautionary measure, Parks Canada is not recommending foot travel through the prairie dog colonies in Grasslands, but the park remains open and the public is being encouraged to continue to visit.
“For people the, risk is low as far as human health effects go. But of course, theoretically, there’s always that potential (for transmission),” said Dr. David Torr, consulting medical officer of health for Cypress Health Region.
“We don’t want it move from a theoretical to a practical risk,” Torr said, explaining people can take precautions to avoid flea bites, such as wearing insect repellent in the park. People should be wearing DEET repellent anyway to prevent the possibility of getting West Nile Virus from mosquitoes, Torr said.
Prairie dog colonies within Grasslands National Park are also closed to pets to reduce the possibility they could pick up infected fleas and spread the disease.
Phil Curry, zoonotic diseases consultant for the Ministry of Health, described plague as something that generally operates at “background” levels.
“Occasionally it does result in large die off of animals. That’s been documented in the United States in some prairie dog colonies,” Curry said.
But Curry said there’s no sign the disease has spread to the rest of the prairie dog colony where the carcass was found in Grasslands.