Patterns associated with season and facilities for atrophic rhinitis and pneumonia in slaughter swine

Three slaughter checks were performed for each of 21 swine producers at 6-month intervals. Two slaughter checks were performed during the winter, and 1 slaughter check was performed during the summer. Lesions of atrophic rhinitis and pneumonia were evaluated during the slaughter checks. Two types of farrowing facilities and 4 types of grower/finisher facilities were used by the swine producers. Lesions of atrophic rhinitis and pneumonia were compared among seasons and among types of facilities. Lesions of both atrophic rhinitis and pneumonia varied with season. Lesions of atrophic rhinitis were more severe among hogs slaughtered in the summer, whereas lesions of pneumonia were more severe among hogs slaughtered in the winter. Lesions of atrophic rhinitis were more severe in hogs farrowed in central, enclosed farrowing houses and finished in enclosed, mechanically ventilated buildings than in hogs farrowed individually in sow huts and finished on dirt lots. Knowledge of disease patterns associated with season and facilities is useful for assessment of herd health status and for implementation of control programs.