Infectious agents associated with rabbit pneumonia: Isolation of amyxomatous myxoma virus strains

Sixty-six rabbits, with no history of vaccination against myxomatosis and w hich had died of pulmonary lesions, were submitted for virological and sero logical tests for Myxoma virus (MV) infection and for bacteriological exami nations. At post mortem, the diagnoses based on observed lesions were as fo llows: acute haemorrhagic pneumonia (38%); acute suppurative bronchopneumon ia (35%); and fibrinohaemorrhagic bronchopneumonia, with fibrinous pleuriti s (27%). MV was isolated from 10% of die rabbits, mainly from those with ac ute haemorrhagic pneumonia. Serological evidence of MV infection was demons trated in 44% of rabbits. Pathogenic bacteria species isolated from lungs w ere Pasteurella (spp. and multocida), Escherichia coli, Bordetella bronchis eptica and Pseudomonas aeruginosa, respectively, from 41, 11, 7 and 6% of s amples. No relationship could be established between the presence of specif ic antibodies to MV and the observed pulmonary lesions or the results of th e bacteriological examinations. A significant trend was established between the severity of the lesions and the results of the bacteriological examina tions. (C) 2000 Harcourt Publishers Ltd.