Fatal hemolytic disease in sheep attributed to Leptospira interrogans serotype hardjo infection

An outbreak of acute hemolytic disease in a large flock of sheep resulted in a mortality of approximately 5% in lambs. A diagnosis of Leptospira interrogans serotype hardjo infection was established on the basis of the presence of leptospires in the urine of one lamb, serologic findings in a guinea pig inoculated with this urine, L. hardjo titers in lambs, and pathologic findings. Prominent necropsy findings included severe icterus, thin watery blood, dark red to black kidneys and severe hemoglobinuria.