There’s a plague infecting Idaho mule deer. This week, the Washington Animal Disease Diagnostic Laboratory (WADDL) at Washington State University confirmed that a blind mule deer found in Custer County, Idaho, back in June is the fifth documented case of a deer with ocular plague, according to Northwest Public Broadcasting.

“There was really a horrendous inflammation in these eyes,” said Kyle Taylor, a pathologist at WADDL and faculty member at the university’s College of Veterinary Medicine. “The severity of it, and because it was in both eyes, reminded me of a paper that came out a number of years ago that mentioned ocular plague in mule deer in both Oregon and Washington.”

Taylor sought clearance to test for plague even though the disease is rare, and contact with it can lead to severe complications and death without early treatment. While Taylor tested other tissue samples, including lung, liver, and heart, the bacteria that causes ocular plague—Yersinia pestis—was only found in the deer’s eyes.

“There was no inflammation in those tissues either,” said Taylor. “So it was only in the eyes, as far as we could tell.”

Deer aren’t usually prone to the disease though, there have been documented cases of plague in western wildlife populations for years, according to Taylor. Despite the discovery, Taylor doesn’t believe it’s a threat to public health.

“Realistically, in most cases, an animal like that would not survive long in the wild,” said Taylor. “So the chances of coming across that kind of animal, it’s very slim to begin with.”