First North American case of staggering disease found in Colorado mountain lion

COLORADO SPRINGS, Colo. (KRDO) – The first North American case of rustrela virus, or "staggering disease," was found in a Colorado mountain lion.

Colorado Parks and Wildlife said in May 2023, they were forced to euthanize a sick mountain lion found in a residential area of Douglas County that was unable to use its back legs. An analysis of the mountain lion's tissue revealed it was sick with rustrela virus.

According to CPW, this virus was recently identified as the cause of “staggering disease,” a usually fatal neurologic syndrome recognized in domestic cats.

The findings were published this week in a report titled "Emerging Infectious Diseases," written by Dr. Karen Fox, a former CPW Wildlife Pathologist and current research scientist with Colorado State University.

In the report, Fox stressed that scientists do not know how widespread the virus could be in cats and wildlife in North America. In Europe, staggering disease has been found in cats as well as other species, such as rodents, marsupials and a donkey.

Now, veterinarians at Colorado State University and Colorado Parks and Wildlife are on the lookout for new cases.

“Now that we know what we’re looking for, it should be easier to find new cases if they are out there,” Fox said. “With continued collaboration, we plan to learn what we can from our colleagues in Europe while we continue to look for new cases of staggering disease here in Colorado.”

CPW asks anyone who believes they see an animal staggerig, having trouble walking or behaving abnormally to contact their local CPW office and report the behavior.