Haemolytic disease in new born calves.

Neonatal haemolytic disease was diagnosed in a Bos indicus cross bred beef herd in south-east Queensland. The evidence suggested that this was due to B. argentina vaccination for babesiosis while non-pregnant or less than one month pregnant. The cows received 5 or 6 vaccinations during their breeding life, which indicated that antibody levels can persist for long periods. The autopsy, histopathological and haematological findings indicated that the mechanism was disseminated intra-vascular coagulation which occurred in calves dying within 24 hours of birth. This resulted in fibrin deposition in pulmonary capillaries and severe pulmonary oedema.