The Plague: There have been 13 plague cases so far this year in the United States - the most since 1994. All of them have been in the West, where plague is epizootic in some areas, such as Colorado. The CDC offers this advice:

The majority of exposures to plague occur in the peridomestic environment ; free-roaming pets that bring infected rodent fleas into the home have been suspected as a potential source of human infections. Persons residing in areas where plague is endemic should keep their dogs and cats free of fleas through regular use of flea treatments and by keeping them indoors. Year-round rodent control should be conducted, including rodent proofing of structures and eliminating food sources (e.g., pet food or garbage) and harborage (e.g., piles of wood or debris) in the peridomestic environment. Persons who participate in outdoor recreational activities, particularly rabbit hunting, in areas of epizootic plague activity also are at risk for plague. Personal protective measures include using insect repellents, wearing protective clothing, and avoiding sick or dead animals. In areas of epizootic plague activity, public health officials should treat rodent habitats with insecticides and should educate the public regarding plague prevention and control. "

We have antibiotics that can handle the plague now (if it's recognized early enough), but it used to strike fear in the hearts of men.