Pasteurellosis in Pigs
- Pasteurellosis in pigs is usually caused by *Pasteurella multocida* and most often affects the respiratory tract.
- It commonly shows up as secondary bacterial pneumonia after another problem such as mycoplasmal pneumonia, swine influenza, or other respiratory irritation.
- Some strains are also involved in atrophic rhinitis, which can cause sneezing, nasal discharge, tear staining, poor growth, and facial changes in young pigs.
- Warning signs include cough, fever, fast or labored breathing, reduced appetite, lethargy, and worsening nasal discharge.
- A veterinary visit is important because treatment often depends on the pig's age, severity, herd exposure, and whether culture or other testing is needed.
What Is Pasteurellosis in Pigs?
Pasteurellosis in pigs is a bacterial disease most often linked to Pasteurella multocida. In many pigs, this bacterium lives in the upper airway without causing obvious illness. Trouble starts when the respiratory tract is already stressed or damaged. Then the bacteria can move deeper into the lungs and cause bronchopneumonia, sometimes along with pleuritis or pericarditis.
In practical terms, pig pasteurellosis is often part of a bigger respiratory picture rather than a stand-alone infection. It is commonly seen after problems such as mycoplasmal pneumonia, swine influenza, or other infections that weaken normal airway defenses. In young pigs, toxigenic strains of P. multocida can also contribute to atrophic rhinitis, especially when Bordetella bronchiseptica is involved.
For pet parents, that means signs can range from mild sneezing and nasal discharge to serious breathing difficulty. Some pigs mainly show upper-airway signs, while others develop fever, cough, poor appetite, and pneumonia. Because pigs can decline quickly once breathing becomes hard, early veterinary guidance matters.
Symptoms of Pasteurellosis in Pigs
- Sneezing
- Nasal discharge
- Tear staining or watery eyes
- Cough
- Fast or labored breathing
- Fever
- Lethargy
- Reduced appetite or poor growth
- Facial distortion or shortened snout in young pigs
- Sudden worsening, purple skin discoloration, or collapse
See your vet immediately if your pig has open-mouth breathing, obvious effort to breathe, blue or purple discoloration, collapse, or stops eating. Respiratory disease in pigs can worsen fast, and smaller pet pigs may have less reserve when their lungs are affected.
Even milder signs deserve attention if they last more than a day or two, spread to other pigs, or affect a young pig. Sneezing and nasal discharge can look minor at first, but they may be part of atrophic rhinitis or the early stages of pneumonia.
What Causes Pasteurellosis in Pigs?
Pasteurella multocida is the main bacterium involved. The important detail is that it is often an opportunist. Many pigs carry it in the upper respiratory tract, but disease is more likely when the normal airway defenses have already been disrupted.
Common triggers include mycoplasmal pneumonia, swine influenza, and other respiratory infections. Stress also matters. Mixing pigs, transport, crowding, poor ventilation, dusty bedding, ammonia buildup, and sudden temperature swings can all make respiratory disease more likely. In miniature pet pigs, exposure at fairs, exhibitions, or other pig gatherings can increase infectious risk.
When toxigenic strains of P. multocida are present with Bordetella bronchiseptica, young pigs may develop atrophic rhinitis instead of, or in addition to, pneumonia. That form tends to affect the nose and facial bones more than the lungs. Your vet will help sort out which pattern best fits your pig.
How Is Pasteurellosis in Pigs Diagnosed?
Diagnosis starts with a hands-on exam and a careful history. Your vet will ask about age, housing, recent stress, contact with other pigs, vaccination status, and whether more than one pig is affected. They will listen to the lungs, check temperature, and look for nasal discharge, tear staining, cough, facial asymmetry, or poor body condition.
Because Pasteurella can be part of a mixed respiratory disease complex, testing often focuses on finding both the bacterium and any underlying problem. Depending on the case, your vet may recommend nasal or deep respiratory samples, bacterial culture with susceptibility testing, PCR panels for other swine respiratory pathogens, or imaging if available. In herd or farm settings, necropsy findings and recovery of Pasteurella from lesions are especially important.
Testing helps guide treatment choices instead of guessing. That matters because some pigs need only outpatient care, while others need broader workups for mycoplasma, influenza, pleuritis, or severe pneumonia. In the US, a bacterial culture commonly adds about $30-$35, and food-animal susceptibility testing often adds about $25-$30 through veterinary diagnostic labs, on top of exam, sample collection, and treatment costs.
Treatment Options for Pasteurellosis in Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Office or farm-call exam
- Temperature, breathing assessment, and basic respiratory exam
- Empiric antibiotic selected by your vet when pasteurellosis is suspected
- Anti-inflammatory medication if appropriate
- Home isolation, improved ventilation, dust reduction, and supportive feeding/hydration guidance
- Short recheck if signs are not improving
Recommended Standard Treatment
- Full veterinary exam and treatment plan
- Targeted sample collection for bacterial culture and susceptibility when feasible
- Respiratory pathogen testing as indicated
- Prescription antibiotic plan based on likely organisms and pig age/use
- Anti-inflammatory or fever control medication if appropriate
- Structured isolation and environmental correction plan
- Recheck exam to confirm response
Advanced / Critical Care
- Urgent or emergency evaluation
- Hospitalization for oxygen support or intensive monitoring when available
- Injectable medications and fluid support as directed by your vet
- Expanded diagnostics such as imaging, broader PCR testing, or multiple-site sampling
- Necropsy and herd-level investigation if deaths occur or multiple pigs are affected
- Step-up treatment for severe pneumonia, pleuritis, or nonresponse to first-line care
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Pasteurellosis in Pigs
Bring these questions to your vet appointment to get the most out of your visit.
- You can ask your vet whether my pig's signs fit pneumonia, atrophic rhinitis, or a mixed respiratory disease.
- You can ask your vet what underlying infection or stressor may have allowed *Pasteurella* to cause disease.
- You can ask your vet whether culture and susceptibility testing would change the treatment plan in this case.
- You can ask your vet which treatment option fits my pig's severity, home setup, and budget.
- You can ask your vet what breathing changes mean I should seek urgent re-evaluation.
- You can ask your vet how long isolation should last and how to reduce spread to other pigs.
- You can ask your vet whether ventilation, bedding dust, crowding, or ammonia could be making the problem worse.
- You can ask your vet whether vaccines for atrophic rhinitis or other respiratory diseases make sense for my pig or group.
How to Prevent Pasteurellosis in Pigs
Prevention focuses on lowering respiratory stress and controlling the diseases that often come first. Good ventilation, dry bedding, less dust, lower ammonia, and avoiding overcrowding all help protect the airway. Quarantine new pigs before mixing, and be cautious about fairs, exhibitions, and other events where pigs from different sources come together.
Because Pasteurella multocida often acts as a secondary invader, prevention also means managing the bigger respiratory picture. Work with your vet on vaccination plans when appropriate, especially for pigs at higher risk of atrophic rhinitis or mycoplasmal pneumonia. Merck's swine vaccination guidance lists atrophic rhinitis vaccines for breeding animals and piglets in higher-risk settings, and also includes vaccination schedules for Mycoplasma hyopneumoniae.
If one pig becomes sick, isolate that pig promptly, clean shared equipment, and monitor close contacts for cough, sneezing, fever, or appetite changes. Early action can limit spread and may keep a mild case from becoming a more serious pneumonia problem.