"All the affected animals have exhibited some degree of walking abnormally or difficulty coordinating their back legs," the release said.
The FWC said neurological damage has been confirmed in one panther and one bobcat, and trail camera footage shows eight panthers, mostly kittens, and an adult bobcat displaying varying degrees of the condition.
The condition appears to be localized to Collier, Lee, Sarasota and Charlotte counties, FWC officials said.
"While the number of animals exhibiting these symptoms is relatively few, we are increasing monitoring efforts to determine the full scope of the issue," said Gil McRae, the director of FWC's Fish and Wildlife Research Institute.
The FWC said it is testing for various potential toxins, including neurotoxic rodenticide (rat pesticide), as well as infectious diseases and nutritional deficiencies.
"Numerous diseases and possible causes have been ruled out; a definitive cause has not yet been determined. We're working with the U.S. Fish and Wildlife Service and a wide array of experts from around the world to determine what is causing this condition," McRae said.
Officials said the public can help by submitting trail camera footage or other videos that capture animals that appear to have a problem with their rear legs.
Florida panthers are an endangered species native to Florida and the state's official animal.