Vol. 10, Issue 12, Part C (2025)

Atrophic Rhinitis (AR) and bronchitis are significant respiratory diseases of swine that contribute to substantial economic losses through impaired growth, reduced feed efficiency, and increased mortality. AR is a chronic, degenerative disorder of the nasal mucosa characterized by turbinate atrophy, mucosal desiccation, and excessive crust formation, frequently accompanied by the malodor known as ozaena. Although multiple organisms may be involved, the pathogenesis typically begins with colonization by Bordetella bronchiseptica, which promotes mucosal inflammation and ciliary dysfunction, facilitating secondary infection by toxigenic Pasteurella multocida. The dermonecrotoxin produced by P. multocida disrupts bone remodeling, resulting in progressive turbinate destruction, facial deformities, and compromised growth. Epidemiological studies show variable prevalence influenced by housing, ventilation, season, and management practices. Diagnosis relies on clinical evaluation, microbial detection, PCR assays, and histopathology. Treatment strategies include antimicrobial therapy, anti-inflammatory support, and optimized husbandry, while prevention emphasizes biosecurity, vaccination, sanitation, and selective breeding.
Bronchitis in swine arises from complex interactions among viral and bacterial pathogens, including PRRSV, swine influenza virus, PRCV, B. bronchiseptica, and Mycoplasma hyopneumoniae. Coinfections amplify inflammatory responses, leading to more severe pulmonary lesions than single-pathogen infections. Macroscopic lesions commonly present as cranioventral lung consolidation, while microscopic findings range from mild interstitial thickening in single-pathogen infection to severe lymphocytic cuffing, epithelial necrosis, and syncytial cell formation in dual infections. Diagnosis integrates clinical signs with bacterial culture, PCR testing, serology, and histopathology. Management includes appropriate antimicrobial therapy for bacterial agents, environmental control, vaccination, and ongoing herd-level health monitoring. Together, AR and bronchitis exemplify the multifactorial nature of swine respiratory disease and highlight the need for integrated diagnostic, preventive, and therapeutic approaches.