Pulmonary lesions in swine 4. microbiologic and pathologic diagnosis in swine enzootic pneumonia in the state of minas gerais brazil
Nogueira, R.H.G.; Rezende, M.; Reis, R.; Do-Nascimento, E.F.; Chquiloff, M.A.D.
Arquivos da Escola de Veterinaria Universidade Federal de Minas Gerais 32(2): 143-150
A total of 840 swine lungs were examined in Brazilian abattoirs; of these, 143 were selected for further study because of lesions suggestive of swine enzootic pneumonia (SEP). Of the 143, 31 were positive for Mycoplasma hyopneumoniae; the organism was recovered in pure culture from only 2. The remaining isolates were M. hyorhinis (13 animals) or M. hyorhinis and other unidentified bacteria (16 animals). The gross lesions were sharply delineated from the normal tissue and were generally confined to the apical and cardiac lobes. The consolidated areas were dark red to gray. Histologic studies revealed perivascular and peribronchiolar infiltrates of lymphocytes and increased cellularity in the alveolar septa; the alveoli contained macrophages, lymphocytes and desquamated epithelium. In cases considered to be chronic, there were fibroses in the peribronchial areas. Occasionally, neutrophils were present in the alveolar exudate and were considered to be the result of secondary pneumonia.