Prevalence of Antibodies to Swine Influenza Virus, Porcine Adenovirus Type 4 and Haemophilus pleuropneumoniae in Quebec Pig Farms with Respiratory Problems.

The prevalence of antibodies to three etiological agents involved in swine pneumonia was determined in Quebec pig farms which had experienced problems of mild to severe respiratory problems. Of the 350 sera collected from adults pigs, 67.0%, 18.3% and 46.6% had antibody titers to Haemophilus pleuropneumoniae type 1 and/or 5, to porcine adenovirus type 4 and to swine influenza virus, respectively. Comparatively, the serological prevalence rates for Haemophilus pleuropneumoniae, porcine adenovirus and swine influenza virus were 43.7%, 0% and 3.3% in farms not experiencing respiratory problems.