leptospirosis (lĕpˌtəspĪrōˈsĭs) [key], febrile disease caused by bacteria of the genus Leptospirae. The disease occurs in dogs, cattle, pigs, sheep, goats, and horses and is transmissible to humans. It is most common where the climate is warm and humid, soils are alkaline, and there is abundant surface water. The source of infection in farm animals is usually through pastures, drinking water, or feed, when contaminated by infected urine, and is often a work-related risk for farmers, sewer and slaughterhouse workers, and vetinarians. Infection may also occur as a result of contact with infected uterine discharges and aborted fetuses, with infected pets, or with contaminated water while swimming or during persistent flooding.
In cattle, pigs, sheep, and goats, the disease is characterized by fever, depression, anemia, and abortion. Horses develop an ocular infection. In dogs the disease causes a severe kidney infection. In humans, typical symptoms include a dry cough, fever and chills, head and muscle aches, and nausea and diarrhea. It is treated with chloramphenicol, erythromycin, or other antibiotics; untreated, it may be life-threatening. Control of leptospirosis depends on the elimination of carrier animals, appropriate hygienic measures, and vaccination of susceptible animals.