Bubonic plague is killing Yellowstone cougars -- and humans can catch it, study says

In Yellowstone, cougars are facing an epidemic of their own -- bubonic plague.

The flea-borne disease, most famous for killing half of Europe during the medieval ages, is showing up in the cougar population inhabiting the Greater Yellowstone Ecosystem, according to a recent study.

Findings suggest it could be widespread. Of the 28 big cats researchers tested, 12 were infected or had been infected, according to the study published in Environmental Conservation.

“This suggests that: (bubonic plague) may be present at higher levels in the GYE than previously assumed,” it said, also adding that plague may be a “significant” cause of death for the animals.

Researchers carried out the study over the course of nine years, following the discovery of two dead cougars, a mother and her cub, in Wyoming, the Smithsonian Magazine said.

The deaths weren’t in and of themselves surprising, lead researcher Mark Elbroch told Livescience.

It was the winter and so starvation was the presumed culprit, but when the true cause of death was discovered, it “was a shocker,” he told the outlet.

Researchers said it’s very unlikely the average person would ever catch plague from a mountain lion, but given that the disease is capable of animal-to-human transmission, they recommended warnings for some.

“We would also emphasize that hunters and others handling pumas in this region should be made aware of the possibility of exposure,” the study said.

Cougar behavior makes them a poor means of transferring diseases to people, but as Elbroch’s team points out, their high rate of infection means the Yellowstone ecosystem itself could be a hotbed of plague.

A Boy Scout came down with plague in 2008 following a camping trip in Yellowstone National Park, the Jackson Hole News & Guide reported.

“Plague is very much a part of the landscape in the western U.S., and wild animals are frequently exposed to it,” a USDA researcher Sarah Bevins told National Geographic. “Human plague infections are still relatively rare ... but untreated plague infections are still just as deadly as they were 500 years ago.”