any of several systemic infections of humans and domestic animals caused by a genus (Leptospira) of spirochetes found in sewage and natural waters, and involving variously the eyes, liver, kidneys, etc.
See leptospirosis in American Heritage Dictionary 4
(lĕpˌtō-spī-rōˈsĭs)
noun
An infectious disease of domestic animals, especially cattle, swine, and dogs, caused by spirochetes of the genus Leptospira and characterized by jaundice and fever.