Control and prevention strategies of porcine respiratory disease complex: current evidence and future directions

Porcine Respiratory Disease Complex (PRDC) is a multifactorial disease with a major economic impact on the global swine industry. Its emergence and progression are strongly influenced by interactions among infectious agents, environmental conditions, and management practices, making its prevention and control particularly challenging. This review summarizes the principal strategies and emerging approaches for PRDC prevention and control, highlights recent advances, and discusses their potential limitations and future research needs. Effective PRDC management requires a comprehensive and multifaceted approach that accounts for the high frequency of coinfections involving multiple pathogens and the overlapping and nonspecific clinical signs associated with respiratory disease. Accordingly, control programs should integrate external and internal biosecurity measures. For external biosecurity, the priority is to prevent pathogen introduction through appropriate animal sourcing, quarantine and acclimation procedures, semen screening, pest control, and management of transport, personnel, and fomites. Within farms, internal biosecurity measures should then limit pathogen transmission through appropriate pig flow and herd management, stocking density control, and optimization of environmental conditions. Because pathogen detection alone does not establish its role in disease, diagnosis should combine clinical, epidemiological, pathological, and laboratory findings. Continued herd-level monitoring, supported by appropriate sampling and laboratory testing, is also essential for identifying changes in pathogen circulation and evaluating control measures. Vaccination remains a cornerstone of PRDC prevention, while emerging vaccine technologies and novel immunization strategies offer promising opportunities to improve protection against respiratory pathogens. Furthermore, growing concerns regarding antimicrobial resistance have intensified the search for alternatives to conventional antibiotics, including probiotics, essential oils, and bacteriophages, which have shown encouraging potential but require further validation under field conditions. Overall, successful PRDC prevention and control depend on recognizing its multifactorial nature and integrating biosecurity, vaccination, management practices, antimicrobial alternatives, and effective monitoring systems. Further research conducted under commercial production conditions will be essential to determine the practical efficacy of emerging approaches and facilitate their incorporation into comprehensive and sustainable PRDC control programs.