Bovine leptospirosis: microbiological and serological findings in aborted fetuses.

Leptospiral infection was diagnosed in 41.6 per cent of 245 randomly selected aborted bovine fetuses and 68.9 per cent of 103 aborted fetuses from farms with abortion problems. Diagnosis was based on combined leptospiral isolates from fetal kidney and eye, and fetal serology and immunofluorescence. Fifty-six of the 58 strains of leptospira isolated belonged to the Hebdomadis serogroup and were similar to serovar hardjo while one of the remaining two strains belonged to the Icterohaemorrhagiae serogroup and the other to the Canicola serogroup. These findings indicate that serovar hardjo infection is a major factor in the aetiology of bovine abortion and that it is possible to isolate this organism from fetal kidney by the careful application of dilution culture technique.