Researchers are trying to determine whether a sexually transmitted disease might have caused the blindness found in at least two mountain lions in the Black Hills.

Steve Griffin, a wildlife biologist with the South Dakota Game, Fish and Parks Department, said tests on two lions are consistent with chlamydia, but nothing is confirmed.

Three lions have been observed so far with opacity in their eyes. Two of them were confirmed blind.

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Griffin said the disease will not be confirmed unless eye swabs or blood samples can be taken from more cats.

Jonathan Jenks, a wildlife and fisheries sciences professor at South Dakota State University, said he has contacted researchers in Wyoming and Florida to see whether any chlamydia cases have been documented in lions.

He has yet to find a documented case, although he said chlamydia is "pretty common in domestic cats."