Submitted to: American Association of Swine Practitioners Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 25, 1999
Publication Date: N/A
Technical Abstract: A study was conducted to examine the effects of co-infection of porcine reproductive and respiratory syndrome virus (PRRSV) and Bordetella bronchiseptica in weaned pigs. Thirty, 3-week-old weaned pigs (10 pigs per group) were inoculated with PRRSV, B. bronchiseptica, or PRRSV and B. bronchiseptica. Ten pigs were kept as uninoculated controls. Clinical signs of coughing and sneezing began sooner, lasted longer, and were more severe for the co-inoculated group than for the groups receiving PRRSV or B. bronchiseptica alone. Elevation in body temperature was greater and lasted longer for the co-inoculated group than for the other groups as well. There was no difference in weight gain between the B. bronchiseptica inoculated group and the control group; however, both the PRRSV inoculated group and the co-inoculated group had lower average daily gains. Five pigs from each group were euthanized at 10 days post inoculation. PRRSV was isolated from all pigs inoculated with the virus. All pigs in the 2 group which received PRRSV had gross evidence of interstitial pneumonia with little difference between the 2 groups. B. bronchiseptica was cultured from the nasal turbinates and trachea of all pigs inoculated with the bacteria. The level of colonization of these 2 sites was comparable between the 2 groups receiving B. bronchiseptica. No pigs in the group which received only B. bronchiseptica had any lung lesions. Three of the pigs in the co-inoculated group had gross evidence of bacterial pneumonia with a cranial ventral distribution. B. bronchiseptica was not isolated from the lung of any pigs which received B. bronchiseptica alone but was isolated from 2 pigs which were co-inoculated, both of which had gross lesions consistent with B. bronchiseptica pneumonia.