Submitted to: Iowa Veterinary Medical Association
Publication Type: Proceedings
Publication Acceptance Date: August 31, 2001
Publication Date: N/A
Technical Abstract: The roles Bordetella bronchiseptica and toxigenic strains of Pasteurella multocida play in atrophic rhinitis are well documented. B. bronchiseptica alone causes a mild to moderate non-progressive form of atrophic rhinitis and leaves the pig more susceptible to infection with toxigenic P. multocida, which causes the more severe progressive form of the disease. The roles these pathogens play in the porcine respiratory disease complex (PRDC) are less clear. B. bronchiseptica is sporadically isolated from the lungs of pigs with PRDC, but it may play a surreptitious role in pre- disposing to respiratory and systemic disease with other pathogens. P. multocida is one of the most common secondary bacteria isolated from cases of PRDC, and it is commonly isolated along with primary pathogens such as Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV). There has been a resurgence of diseases like atrophic rhinitis, M. hyopneumoniae, and Haemophilus parasuis which largely appeare to be under control. There are several theories as to why this is happening. The emergence of viruses such as PRRSV, porcine respiratory coronavirus, and porcine circovirus 2 may have tipped the balance in favor of bacterial pathogens, and management practices designed to lower transmission may have ultimately created naive populations of pigs which are highly susceptible to infection. The purpose here is to discuss the roles B. bronchiseptica and P. multocida play in respiratory disease of pigs and why it is important to determine whether or not they are present.