[Transmission of agents of the porcine respiratory disease complex (PRDC) between swine herds: a review. Part 1--diagnosis, transmission by animal contact].

Knowledge on the different ways of transmitting PRDC pathogens (PRRSV, influenza virus A, PCV 2, M. hyopneumoniae, A. pleuropneumoniae) between swine herds is of special interest for the development of biosecurity measures or the retrospective risk analysis in the framework of activities of the consulting veterinarian. In this literature review the current knowledge of the transmission of PRDC-pathogens is summarized. Since the assessment of investigations into pathogen detection in detail is influenced considerably by the chosen test for the diagnosis, the standard methods of routine diagnostic procedures are described. In this context the limits of the interpretation of the diagnostic findings are especially described in detail. Finally, the transmission caused by pig movement is summarized in this first part of the review.