Porcine respiratory disease complex (PRDC) in Indian pigs: a slaughterhouse survey

Porcine Respiratory Disease Complex (PRDC) is an unequivocally leading cause of economic losses to the pig industry. To investigate the pathogens associated with PRDC, a total of 900 lungs with gross lesions and 125 lungs with no appreciable gross lesions were collected from the abattoirs and subjected to pathological investigation for distribution of lesions/and types of exudates, as well as to molecular confirmation of bacterial and viral pathogens by PCR. The pneumonic lungs showed the higher prevalence of Mycoplasma spp. (31.22%), with evidence of M. hyorhinis, P. multocida (21.33%), S. suis (18.66%), B. bronchiseptica (16.77%), and viral pathogens as porcine circovirus type 2 (PCV2) (28.11%), porcine reproductive and respiratory syndrome virus (PRRSV) (2.7%) and swine influenza virus (SIV) (1.2%). On histopathological examination, high prevalence of bronchopneumonia (37.88%) followed by enzootic pneumonia‑like lung lesions (11.44%), and interstitial pneumonia (7.44%) was recorded in the majority of affected pigs. The winter season was found to be more conducive for highest prevalence of pneumonia as compared to other seasons. The present study reports the high prevalence of PRDC in slaughtered pigs of India. M. hyorhinis showing the EP‑like lesions, PCV2 and their combination were likely to be the prime contributors of PRDC in Indian pigs.