The phrase ‘"Black Death" conjures horror for the sheer number of people who died from plague in medieval times. But, the same disease poses a modern threat to wildlife across the Southwest.
All four species of American prairie dogs are highly susceptible to the fleaborne bacterial infection known as sylvatic plague. When there’s an outbreak, the high mortality rates among prairie dogs can have serious ripple effects among other grassland species … especially endangered black-footed ferrets that depend on prairie dogs for food.
A team at the U.S. Geological Survey’s National Wildlife Health Center and the University of Wisconsin in Madison has completed a three-year study to develop and test a new vaccine against the plague.
The first challenge was how to best deliver the vaccine to 58 prairie dog colonies across seven western states from Arizona to Montana. The solution? Vaccine-laden bait that prairie dogs found irresistible. Peanut butter beat out blueberry and sweet potato as bait.
As in all drug trials, the vaccine was tested against a placebo containing peanut butter but no drug.
The test showed that prairie dogs that ate treated bait were twice as likely as untreated animals to survive a plague outbreak. Researchers hope the percentage of protected animals will increase as vaccine is delivered across larger areas over successive years—potentially using drones and all-terrain vehicles to speed up the process.
If widespread immunity can be established, this will protect not only prairie dogs but also animals that come into contact with them—including dogs and their human owners.