Porcine Atrophic Rhinitis Study Guide

Overview and Clinical Importance

Atrophic rhinitis (AR) is a contagious upper respiratory disease of swine characterized by inflammation and atrophy of the nasal turbinate bones, leading to snout deformation. The condition exists in two distinct clinical forms: nonprogressive atrophic rhinitis (NPAR) caused primarily by Bordetella bronchiseptica, and progressive atrophic rhinitis (PAR) caused by toxigenic strains of Pasteurella multocida (primarily capsular type D, occasionally type A).

The disease was first described in Germany over 170 years ago as "Schnüffelkrankheit" (sniffing disease). While its prevalence has declined substantially due to improved management, vaccination, and early weaning practices, AR remains economically significant in herds where it occurs, causing reduced growth rates, poor feed conversion, and increased susceptibility to secondary respiratory infections.

Etiology

Primary Pathogens

Bordetella bronchiseptica: Aerobic, Gram-negative coccobacillary rod that readily colonizes the nasal passages of swine. Widely distributed in the swine population and often present subclinically. Toxigenic strains produce dermonecrotic toxin (DNT) and adenylate cyclase toxin, causing mild turbinate lesions that are largely reparable by the host.