Fig. 1. Proportions of major pathogens and major pathogen combinations in polymerase chain reaction (PCR)-positive porcine oral fluid samples. PRRSV, porcine reproductive and respiratory syndrome virus; PCV2, porcine circovirus type 2; MHP, Mycoplasma hyopneumoniae. ^*Pathogen combinations were considered positive if the major pathogen and one or more other pathogens were PCR positive. ^†Pathogen combinations were considered positive if one or more pathogens were PCR positive without PRRSV, PCV2, and MHP.