Endangered gray bats may be wiped out within two years, say wildlife officials, after the deadly white-nose disease was found in their population.
The white-nose disease has killed more than five million other hibernating bats in the United States, yet no gray bats appear to have died so far.
The appearance of the syndrome was confirmed by scientists in two counties in Tennessee on Tuesday.
The disease is said to have a mortality rate of up to 90 percent, reported the Boston Globe.
"The news that another federally endangered bat species, the gray bat, has been confirmed with white-nose syndrome is devastating for anyone who cares about bats and the benefits they provide to people," said Dan Ashe, US Fish and Wildlife Service Director, reported Reuters.
The syndrome was first discovered in New York state in 2008 and officials believe that it is caused by a fungus, which was found in the mouths of the dead bats.
Read more on GlobalPost: US confirms first known case of vampire bat rabies
AFP reported that the disease has been found in 19 US states and four Canadian provinces since it was discovered in 2008.
"I've studied bats for 40-something years, and I've never seen anything like this; it's alarming," Thomas Kunz of Boston University told the Boston Globe during the 2008 outbreak.
"It's frustrating and perplexing, because we don't know what it is and we don't know how to control it."
Gray bats have been on the endangered species list in the United States since 1976.
They are seen as essential for the health of other cave-dwelling animals, which feed on their droppings.
The bats are also believed to be critical for protecting farmers' crops from insects, which are the main staple of their diets.