Bovine leptospirosis: a serological and clinical study.

Antibodies to serotypes representing one or more of 10 Leptospira serogroups were detected in the sera of 1766 (49-1 per cent) cows and heifers out of a total of 3600 sera tested. Infection by the Hebdomadis serogroup was the predominant infection; antibodies to serotype sejroe were found in 1503 (41-8 per cent) sera. Antibodies to the Icterohaemorrhagiae (7-7 per cent) and Balllm (7-3 per cent) serogroups were the next most common, while antibodies to the Australis, Javanica, Canicola, Panama, Cynopteri, Pyrogenes and Autumnalis serogroups were detected in a small number of animals. Only the Hebdomadis and Icterohaemorrhagiae serogroups were associated with clinical disease.