In response to a case of plague in prairie dogs in Saskatchewan's Grasslands National Park, park officials are dusting prairie dog burrows with insecticide to try to control fleas. A single case of plague, a serious bacterial infection caused by Yersinia pestis, was identified in a prairie dog in the park earlier this summer. Plague is present in some areas of North America, but it's rare in Saskatchewan. It circulates in wild small mammals, and prairie dogs are particularly susceptible to infection. The main mode of transmission is via fleas, which feed off infected animals, then bite and infect other animals.
Prairie dog numbers at the park have dropped by 50-70% this summer, however it's not known whether plague is involved in this, as there has also been a drought. It's fair to assume, though, that if there has been one case of plague found in the park, there have probably been many other undiagnosed cases. Whether or not plague is responsible for the large drop in prairie dog numbers, measures to try to reduce plague transmission are a good idea because of the impact it can have on the prairie dog population (and those of other wild mammals), as well as people or pets that may venture into the area. Anyone or anything walking through the area could plausibly be bitten by an infected flea. The odds are probably pretty low, but park officials are trying to keep people and pets out of the park to reduce this risk.