Pasteurella haemolytica septicaemia in sheep.
About 60 of 650 mixed-sex, 12-month-old, Bond sheep died during 3 weeks on a farm in New South Wales in Feb and Mar 1992. Diagnosis of septicaemia caused by P. haemolytica biotype T was made based on observation of sudden death, isolation of this organism from a range of tissues from 4 sheep, and the histological detection of peracute, multifocal, embolic, necrotising lesions in the lung and liver associated with bacteria of consistent morphology. It is proposed that stress induced by changes in paddock and diet as well as confinement for drenching and vaccination during the first 5 days of the outbreak may have been contributed to cause the disease. This appears to be the first report of septicaemia caused by P. haemolytica in Australia.