“Staggering Disease” Found In Colorado Mountain Lion

“Staggering Disease” Found In Colorado Mountain Lion

By Dave Shaffer

In a News Release just posted by Colorado Parks and Wildlife (CPW), they confirmed the first finding of rustrela virus in a mountain lion in North America.

In May of 2023, CPW euthanized a sick mountain lion in Douglas County (vic Castle Rock, between Denver and Colorado Springs) that was unable to use its hind legs. An analysis of tissues from the mountain lion revealed the presence of the rustrela virus, which was recently identified as the cause of “staggering disease,” a usually fatal neurologic syndrome recognized in domestic cats.

The lead author on the paper, former CPW Wildlife Pathologist Dr. Karen Fox, said that the diagnosis of staggering disease was challenging, and final confirmation was only possible through collaboration with researchers at the Friedrich-Leoffler-Institut in Germany.    

Fox, currently a research scientist with Colorado State University, (CSU) emphasized that scientists don’t yet know how widespread the virus is in either domestic cats or wildlife populations. In Europe, rustrela virus causes staggering disease in cats, but also has been found in a wide range of other species, including rodents, a donkey and marsupials. 

“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.”

Veterinarians at Colorado State University and Colorado Parks and Wildlife will be looking carefully for new cases. If members of the public observe mountain lions that are staggering, having trouble walking or behaving abnormally, they should contact their local Colorado Parks and Wildlife office to speak with a wildlife officer and report the behavior.

You can read more on the study here:
 A new study published this week in the journal “Emerging Infectious Diseases”