Abstract
Twenty mother dogs, and their 19. fetuses and 57 newborn puppies were examined by the indirect hemagglutination (IHA) test for the transfer of anti-Dirofilaria immitis antibody from mothers to their offspring. The antibody was shown to be passively transferred via colostrum to the puppies and to persist in the puppies for approximately two months. On the other hand, no antibody was detected in the fetuses even when their mothers had high titers. The time-course studies indicated that, on the day of parturition, the colostral IHA titer was identical with that of the maternal serum and also that, within the first 5 to 7 days, the titers of maternal sera rapidly declined and then gradually decreased until 48 days after parturition.
