The geographical distribution and frequency of lesions grossly diagnosed as actinogranuloma were determined in cattle slaugthered in the State of Rio Grande do Sul, Brazil. Of 7.326.902 cattle slaugthered during 1980 to 1987, 84.044 (1.15%) showed actinogranuloma-like lesions. No significant differences were detected in prevalence between years or among the different regions of the State. Specimens from 187 cattle with actinobacillosis-like lesions collected in three abattoirs, were studied histologically. On 159 cattle with granulomatous lesions, actinobacillosis was diagnosed in 181 (82.39%), staphylococcic pyogranuloma in 13 (8.18%) and tuberculosis in 15 (9.43%). Granulomatous lesions were not observed in the histological sections of 28 (17.61%) animals. Bacteriological examinations were performed on 29 samples. Actinobacillus lignieresii was isolated from 19 (65.52%) and Staphylococcus aureus from 5 (17.24%). No bacteriological growth was obtained on blood agar from the other 5 specimens. The histological study confirmed the diagnosis of actinobacillosis and staphylococcic pyogranuloma from the A. lignieresii and S. aureus positive samples, respectively. The 5 samples that were bacteriologically negative after 96 hours incubation were histologically diagnosed as tuberculosis.
Actinobacillosis; staphylococcic pyogranuloma; actinogranuloma; cattle
