Frequency of occurrence of pneumonia associated agents and their correlation with clinical and pathological-anatomical findings in pigs

The aim of this study was to investigate the incidence and influence of different causative organisms involved in the development of pneumonia and bronchopneumonia in pigs. Bronchoalveolar lavage fluid (BALF) from 339 pigs was examined molecular-biologically and culturally. The evaluation considered the following pathogens: Mycoplasma (M.) hyopneumoniae, Mycoplosma (M.) hyorhinis, PRRSV (US-Type), PRRSV (EU-Type), PCV-2, Influenzavirus Type A, alpha-haemolytic Streptococci, P-haemolytic Streptococci, Pasteurella (P.) multocida, Bordetella (B.) bronchiseptica, Hoemophilus (H.) parasuis and Actinobacillus (A.) pleuropneumoniae. This was followed by a pathological-anatomical examination in 168 pigs. Pathologicalanatomical examination was evaluated for possible interstitial pneumonia, catarrhal-purulent bronchopneumonia and pleuritis.(x-haemolytic Streptococci, PCV-2, H. parosuis, M. hyorhinis, M. hyopneumoniae, B. bronchiseptica, PRRSV (US-Type), P multocida, PRRSV (EU-Type) and Influenzavirus Type A were evident in descending incidence in the BALF.A.pleuropneumoniae were only isolated culturally in two cases in the BALF. The frequency and semiquantitative detection rate in the bacteriological culture of a-haemolytic Steptococci, M. hyopneumoniae, P.multocida and B. bronchiseptica correlated significantly with the ascertained clinical evaluation score and the pathological-anatomical examination score. M. hyorhinis and Influenzavirus Type A only correlated with the severity degree of clinical appearance, while PCV-2 and PRRSV (US-Type) correlated with the frequency of pathological-anatomical changes. The higher the clinical score, the higher was the number of animals ascertained with five or more different pathogens. The more different causal agents were isolated in the BALF of one animal, the higher was the average pathological-anatomical examination score. For the diagnosis of pneumonia, especially when analysing facultative pathogens or secondary pathogens, a useful interpretation of analysis results is only possible in connection with a clinical and pathological evaluation.