OK, OK, so ferrets aren’t mice, and they’re not even rodents, but the endangered black-footed ferret is one of the rarest mammals in North America, and they’ve got the plague.
It’s the sylvatic plague, to be exact, which is an exotic flea-borne disease that can be fatal for the ferrets and their primary food source, prairie dogs.
As of June, according to the U.S. Forest Service, the epizootic (that’s the almost-too-cutesy term for the animal version of a human epidemic) had infected prairie dog habitats and black-footed ferret colonies across 9,000 acres in the Buffalo Gap National Grasslands in southwestern South Dakota. Before the outbreak, population surveys placed at least 290 ferrets living in the region, but researchers do not know yet how many ferrets have died in the plague. In the past, similar outbreaks have depleted entire prairie dog colonies and the black-footed ferrets that eat them.
So for the first time, biologists are vaccinating wild ferrets with an antidote against the plague that was developed for humans by the U.S. Army; it’s currently being tested and modified for animals.
“Although the plague vaccine is still experimental in wildlife, we hope its use during this epizootic will protect as many ferrets as we can capture in the field and boost ferret survival during this critical period,” said Christopher Brand, research chief of the U.S. Geological Survey National Wildlife Health Center.
So far, biologists have captured and vaccinated 40 black-footed ferrets since the outbreak began. The vaccine is administered to prairie dogs and black-footed ferrets through a first shot and a booster shot about a month later (no word on how much time the animals have to kill in the waiting room beforehand).
The National Wildlife Health Center is also developing an oral vaccine for prairie dogs’ bait, which would mean humans wouldn’t have to handle the animals. And that’s no small thing: The same bacterium that sickens ferrets and prairie dogs also causes plague in humans. Each year, about five to 15 people get the plague, which can be treated with antibiotics; last November, a National Park Service biologist died after conducting a necropsy on a mountain lion that later tested positive for plague.
Biologists are also investigating the efficacy of spraying insecticide in prairie dog colonies to reduce the flea populations.
“We’ve had experience with burrow dusting in other areas, and we know dusting protects both species from plague during these outbreaks,” said Dean Biggins, a research ecologist and black-footed ferret expert at the USGS Fort Collins Science Center in Colorado.
One measure of the project’s urgency is the number of federal agencies and private organizations that have lined up to lessen the outbreak’s impact. The USGS, Forest Service, National Park Service, U.S. Fish and Wildlife Service, and the Animal and Plant Health Inspection Service are being joined by conservation groups such as the World Wildlife Fund, Defenders of Wildlife, Prairie Wildlife Research and the Prairie Dog Coalition.