Experimentally induced porcine proliferative and necrotising pneumonia with an influenza A virus
Girard, C.; Morin, M.; el Azhary, Y.
Veterinary Record 130(10): 206-207
1992
ISSN/ISBN: 0042-4900 PMID: 1324542 Document Number: 390898
Preliminary studies to characterize the pathogenic role of an influenza virus type A isolated from pigs with proliferative and necrotising pneumonia are described. A total of 26 pigs including one-day-old caesarean derived colostrum deprived pigs, unweaned one-day-old pigs and 5-week-old specific pathogen free (SPF) pigs were either inoculated intratracheally with 105 TCID50 of the isolate (17 pigs) or used as controls (9 pigs). Pigs were killed 3 and 17 days after infection. Respiratory signs were seen in unweaned infected pigs. PM examination revealed focal pneumonic lesions in the cranial lobes of both lungs in 7 infected pigs. Histological examination revealed lesions of proliferative and necrotising pneumonia (PNP). Lesions were not as extensive as in field cases of the disease. The influenza virus was detected in 4 of these pigs by an indirect immunofluorescence technique and the virus was reisolated from the lungs of 6 infected pigs. Lesions of PNP and the influenza virus were not demonstrated in the control pigs.