Antibodies to Leptospira in the sera of aborted bovine fetuses.

Antibodies to Leptospira serotypes were detected in sera from 15 (6.9 per cent) of 218 aborted fetuses, but were not detected in the sera from 196 non-aborted fetuses. Fourteen (6.4 per cent) sera from the aborted fetuses had antibodies to strains belonging to the Hebdomadis serogroup and 1 (0.5 per cent) had antibodies to a strain belonging to the Icterohaemorrhagiae serogroup. These antibodies were predominantly immunoglobulin M whereas in the dams, antibodies belonged to both immunoglobulin M and G classes.