Lab tests at the University of Wyoming confirmed the cat in Johnson County was infected with plague, according to the Wyoming Health Department.
“The cat’s home is in Kaycee and the animal is known to wander outdoors,” officials confirmed on the department’s website.
The other plague infections in felines occurred in Sheridan and Campbell counties.
Plague is a serious and potentially deadly bacterial infection in both people and animals if they don’t receive antibiotic treatment as quickly as possible, according to state health officer and epidemiologist Dr. Alexia Harrist.
"The disease can be passed to humans from ill animals and by fleas coming from infected animals. We are letting people know of the potential threat in the cat's home area, as well as across the state," Harrist said.
Plague is rare in humans but occurs naturally in the western U.S., where rodents, and subsequently fleas, become infected.
Six human cases of plague have been diagnosed in Wyoming since 1978, with the last one in 2008. An average of seven human plague cases occur every year in the U.S.