A sick mountain lion euthanized by Colorado Parks and Wildlife officials in Douglas County last year was the first confirmed case of staggering disease in North America, the agency said in a news release Tuesday.

Staggering disease, a usually fatal neurologic syndrome seen in domestic cats in Europe, is caused by the rustrela virus and is marked by animals staggering, having trouble walking or behaving abnormally.

It’s also been found in rodents, a donkey, marsupials and zoo animals including lions, according to CPW.

Wildlife officers first received reports of the sick mountain lion in a residential area of Douglas County on May 12, 2023 and found that it was struggling to move or put weight on its back legs, according to the study published in a Centers for Disease Control and Prevention journal this week.

The mountain lion was euthanized and tested for a variety of diseases, all of which came back negative. Because the symptoms were similar to staggering disease seen in Europe, wildlife officials sent tissue samples to the Friedrich-Leoffler-Institut in Germany, where researchers confirmed the diagnosis.

Colorado scientists don’t yet know how widespread the virus is in domestic cats or wildlife, said Colorado State University research scientist Karen Fox, the study’s lead author and former CPW wildlife pathologist.

“Now that we know what we’re looking for, it should be easier to find new cases if they are out there,” Fox said in a statement. “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.”

Anyone who sees mountain lions that are staggering, having trouble walking or behaving abnormally can report them to their local Colorado Parks and Wildlife office.

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Originally Published: July 17, 2024 at 1:25 p.m.