Bordetella bronchiseptica Respiratory Disease in Pigs

Bordetella bronchiseptica is a bacterial respiratory pathogen that affects the upper airways of pigs and can also contribute to pneumonia. In many pigs, infection is mild. Still, it matters because it damages the lining of the nose and airways, interferes with normal clearance of germs and debris, and can make it easier for other respiratory pathogens to take hold.

In pigs, this bacterium is closely linked with atrophic rhinitis, especially in young piglets. On its own, Bordetella bronchiseptica is usually associated with a mild, nonprogressive form that may cause temporary turbinate damage. When it occurs alongside toxigenic Pasteurella multocida, disease can become more severe and permanent, with snout distortion and poorer growth.

It can also be part of the broader porcine respiratory disease complex, where several infections and environmental stressors overlap. That means a pig with Bordetella may not look severely ill at first, but the infection can still reduce thriftiness, worsen coughing or nasal signs, and increase the risk of secondary disease. Your vet can help sort out whether Bordetella is acting alone or as part of a mixed respiratory problem.

The direct cause is infection with the bacterium Bordetella bronchiseptica. It spreads mainly through close contact, respiratory secretions, and contaminated environments. In herd settings, transmission is easier when pigs are crowded, stressed, recently mixed, or housed in areas with poor ventilation.

Young pigs are often affected most noticeably because their airways are still developing and their immune protection may be limited. Merck notes that acute signs of atrophic rhinitis often appear around 3 to 8 weeks of age, and herd severity is influenced by immune status, management, and whether toxigenic Pasteurella multocida is also present.

Environmental irritants can make disease worse. Dust, ammonia, damp housing, temperature swings, and poor air quality all stress the respiratory tract. Bordetella can also act as a predisposing infection, meaning it damages the nasal lining and cilia so other pathogens can colonize more easily. That is one reason your vet may look for coinfections such as Pasteurella, Mycoplasma hyopneumoniae, PRRS-related disease, or other causes of porcine respiratory disease complex.

Diagnosis starts with a history and physical exam. Your vet will look at age group, housing, recent additions to the group, vaccination history, and whether signs are limited to sneezing and discharge or have progressed to poor growth, facial changes, or pneumonia. In pigs with suspected atrophic rhinitis, the pattern of sneezing, tear staining, nosebleeds, and snout changes can be very helpful.

Testing is often needed because Bordetella is commonly part of a mixed respiratory picture. Your vet may collect nasal swabs, deep nasal samples, tonsil or lung samples, or postmortem tissues for bacterial culture and sometimes PCR or susceptibility testing. In herd problems, necropsy and examination of the nasal turbinates or lungs can be especially useful.

If progressive atrophic rhinitis is a concern, your vet may also recommend testing for toxigenic Pasteurella multocida, because that coinfection changes prognosis and prevention planning. Imaging is not routine for every pig, but radiographs or ultrasound may be considered in valuable pet pigs or severe pneumonia cases. The goal is not only to identify Bordetella, but also to understand whether it is the main problem or one piece of a larger respiratory outbreak.

Prevention focuses on biosecurity, air quality, and herd management. New pigs should be sourced carefully and quarantined before joining the group. Avoid mixing age groups when possible, because younger pigs are more vulnerable and older pigs may shed organisms without obvious illness. Good ventilation matters a great deal. Reducing dust, ammonia, damp bedding, and overcrowding helps protect the airway lining that Bordetella targets.

Cleaning and disinfection are also important, but they work best when paired with practical management. Keep feeders and waterers clean, remove soiled bedding promptly, and reduce stress from transport, abrupt diet changes, and temperature swings. If one pig is sick, separate that pig when feasible and handle healthy pigs first.

For herds with recurring problems, your vet may discuss vaccination strategies, especially where atrophic rhinitis is a known issue. Prevention plans may also include monitoring breeding stock, reviewing sow immunity, and testing for other respiratory pathogens that commonly travel with Bordetella. The best prevention program is the one your vet tailors to your pigs, housing setup, and local disease pressure.