The prevalence of pathogens and PCV2 related pathologies in cases of porcine complex respiratory disease (PRDC) and post-weaning multisystemic wasting syndrome (PMWS)

Abstract

The objective of this study was to investigate the prevalence of pathogens and the PCV2-related
pathologies in cases of complex respiratory disease (PRDC) and post-weaning multisystemic wasting
syndrome (PMWS). The tissue and blood specimens from the suspecting pigs with the clinical signs
were collected from 90 different pig farms in several provinces. The screening results showed that PCV2
accounted for the highest detection rate at 75.6% (68/90) by farm and 62.4% (98/157) by case. The
prevalence of PRRSV, MH and HP by farm and case was high in descending order and final was CSFV.
The double infection accounted for the highest rate by farm and by case (11.1 - 44.4% and 8.2 - 41.8%,
respectively), followed by co-infection with 3 pathogens (6.3 -23.8% by farm and 4.1 - 16.3% by case).
The major clinical signs were observed including respiratory failure, stunting, ruffled hair, dermatitis and
diarrhea with difference (P = 0.000) between single PCV2 infection compared with PCV2 co-infected with
other pathogens. The proportion of specific gross and histological lesions at lymph nodes was the most
dominant, followed by lung pneumonia and the difference was between cases of single PCV2 infection
compared with cases of PCV2 co-infection corresponding to P = 0.000 and P = 0.001.