Atrophic Rhinitis of Swine

Definition of the disease: Atrophic rhinitis is an infectious disease of swine characterised by serous to mucopurulent nasal discharge, shortening or twisting of the snout, atrophy of the turbinate (conchal) bones and reduced productivity. It may occur enzootically or more sporadically, depending on a variety of factors including herd immunity. The most severe progressive form is caused by infection with toxigenic strains of Pasteurella multocida alone or in combination with Bordetella bronchiseptica. Infections with B. bronchiseptica alone can cause a mild to moderate form with nonprogressive turbinate bone atrophy. Turbinate atrophy may only be obvious at slaughter or may be detected in the live animal by use of radiography or tomography. Environmental and management factors also contribute to the severity and incidence of this disease. A large proportion of apparently normal pig herds may be infected with B. bronchiseptica or nontoxigenic P. multocida and show a mild degree or low prevalence of turbinate atrophy.