An oral vaccine may soon be in use to protect prairie dogs from the plague. The U.S. Fish and Wildlife Service says in a release that prairie dogs in the wild are less likely to develop sylvatic plague if they are given peanut-butter-flavored bait containing a vaccine against the disease. The Fish and Wildlife Service, Colorado Parks and Wildlife, and other entities have collaborated on the vaccine in order to help endangered black-footed ferrets, which depend on prairie dogs for food. However, the vaccine may also aid in recovering or protecting prairie dog species that are declining or at risk. The Fish and Wildlife Service says it will soon be used on thousands of acres in Arizona, Colorado, Utah, Wyoming, and some other western states.