Enzootic Pneumonia in Pigs
- Enzootic pneumonia is a contagious, usually chronic respiratory disease in pigs most often linked to Mycoplasma hyopneumoniae.
- A dry cough, slower growth, reduced feed efficiency, and coughing that gets worse when pigs are moved are classic clues.
- Many pigs stay bright and keep eating early on, so herd-level performance changes can matter as much as obvious illness.
- Diagnosis often combines history, lung sounds, herd pattern, and testing such as PCR on nasal, tracheal, or lung samples.
- Treatment usually focuses on supportive care, improving air quality, and vet-directed antimicrobials when secondary bacterial infection is a concern.
What Is Enzootic Pneumonia in Pigs?
Enzootic pneumonia is a long-lasting, contagious lung disease of pigs that is most commonly associated with Mycoplasma hyopneumoniae. Your vet may also call it mycoplasmal pneumonia. It tends to spread within groups of pigs and become an ongoing herd problem rather than a one-time event.
This disease often causes a persistent dry cough, especially when pigs are excited or moved. Some pigs look only mildly affected, but they may grow more slowly, convert feed less efficiently, and be more vulnerable to other respiratory infections. That is one reason enzootic pneumonia is considered part of the broader porcine respiratory disease complex.
In pet pigs and small hobby herds, the pattern can be easy to miss at first. A pig may seem active and still eat well, yet keep coughing for weeks. In larger groups, the first clue may be that several pigs are coughing or that finishing pigs are not doing as well as expected.
Because other infections can look similar, your vet will usually focus on the whole picture: age, exposure history, housing, ventilation, stress, and whether secondary bacteria or viruses may also be involved.
Symptoms of Enzootic Pneumonia in Pigs
- Dry, nonproductive cough
- Coughing that is more obvious when pigs are roused, moved, or exercised
- Slower growth or poor weight gain
- Reduced feed efficiency or falling behind pen mates
- Mild increased breathing effort
- Fever, lethargy, or loss of appetite when secondary infection is present
- Noticeable respiratory distress, open-mouth breathing, or blue-tinged skin
Many pigs with enzootic pneumonia have a chronic dry cough and otherwise look fairly normal early on. That can make the condition seem mild even when lung irritation is affecting growth and daily comfort. Signs often become more obvious after transport, mixing, weather changes, dusty bedding, or poor ventilation.
See your vet immediately if your pig is breathing hard, stretching the neck to breathe, refusing food, acting weak, or showing a blue or gray tinge to the skin or gums. Those signs can mean severe pneumonia, a secondary infection, or another urgent respiratory problem.
What Causes Enzootic Pneumonia in Pigs?
The main cause of enzootic pneumonia is Mycoplasma hyopneumoniae, a bacteria-like organism that attaches to the tiny hair-like structures lining the airways. This damages the normal clearing system of the respiratory tract, so mucus, debris, and other germs are harder to remove.
Once the airways are irritated, pigs are more likely to develop more severe disease from secondary bacteria such as Pasteurella multocida and from other respiratory pathogens involved in the porcine respiratory disease complex. In real-world cases, the cough and lung damage are often the result of more than one problem happening at the same time.
Spread usually happens through close contact with infected pigs, including sow-to-piglet transmission and transmission after pigs are mixed. Crowding, poor ventilation, dust, temperature swings, transport stress, and introducing new pigs without quarantine can all increase the chance of disease.
The organism does not survive well forever in the environment, but it can still move efficiently between pigs when biosecurity is weak. That is why prevention is not only about medication. Housing, airflow, stocking density, and herd management matter a great deal.
How Is Enzootic Pneumonia in Pigs Diagnosed?
Your vet will usually start with a physical exam, a review of coughing patterns, and questions about age group, recent stress, new pig introductions, and housing conditions. A dry cough in multiple pigs, especially in growing pigs, raises suspicion, but it is not enough by itself to confirm the cause.
Diagnosis often includes PCR testing on appropriate samples such as nasal, tracheal, or lung samples, depending on the situation and what your vet can safely collect. In herd investigations, your vet may also recommend serology such as ELISA to look at exposure patterns, although antibody testing is usually more helpful at the herd level than for a single pig.
If a pig dies or is euthanized, lung examination can be very helpful. Enzootic pneumonia often causes characteristic cranioventral lung consolidation, and laboratory testing on lung tissue can help confirm Mycoplasma hyopneumoniae while also checking for other pathogens.
Because several swine respiratory diseases overlap, your vet may recommend additional testing to rule out influenza, PRRS-related disease in production settings, or bacterial pneumonia. The goal is not only to name the organism, but also to understand how severe the outbreak is and what practical control steps fit your pig or herd.
Treatment Options for Enzootic Pneumonia in Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Veterinary exam and basic respiratory assessment
- Isolation from newly introduced or obviously sick pigs when practical
- Environmental changes such as better ventilation, lower dust, dry bedding, and reduced crowding
- Monitoring temperature, appetite, breathing effort, and cough frequency
- Targeted medication plan from your vet if signs suggest secondary bacterial involvement
Recommended Standard Treatment
- Veterinary exam plus diagnostic testing such as PCR and, when appropriate, herd-level serology
- Vet-directed antimicrobial plan when indicated for mycoplasma-associated disease or secondary bacterial pneumonia
- Supportive care plan for hydration, appetite support, and stress reduction
- Review of ventilation, stocking density, quarantine, and cleaning practices
- Vaccination discussion for at-risk pigs or herd mates where appropriate
Advanced / Critical Care
- Hospitalization or intensive on-farm veterinary support for pigs with respiratory distress
- Oxygen support, injectable medications, and close monitoring
- Thoracic imaging or expanded diagnostics when available and appropriate
- Necropsy and comprehensive herd workup if deaths occur
- Detailed herd-control planning that may include quarantine protocols, strategic vaccination, and long-term biosecurity changes
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Enzootic Pneumonia 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 cough pattern fits enzootic pneumonia or if another respiratory disease is more likely.
- You can ask your vet which tests would be most useful right now, such as PCR, serology, or lung testing if a pig has died.
- You can ask your vet whether secondary bacterial infection is likely and how that changes treatment options.
- You can ask your vet what housing or ventilation changes would make the biggest difference in my setup.
- You can ask your vet whether other pigs in the group should be monitored, tested, separated, or vaccinated.
- You can ask your vet what warning signs mean I should seek urgent care right away.
- You can ask your vet what realistic recovery timeline to expect for coughing, growth, and return to normal activity.
- You can ask your vet how to quarantine new pigs and reduce the chance of bringing respiratory disease into the group.
How to Prevent Enzootic Pneumonia in Pigs
Prevention starts with biosecurity and air quality. Quarantine new pigs before mixing, avoid unnecessary nose-to-nose contact with outside pigs, and work with your vet on a plan for testing or acclimation when adding animals. Good ventilation, lower dust, dry bedding, and avoiding overcrowding can reduce respiratory stress and help pigs clear normal airway debris more effectively.
Management style matters too. In production settings, all-in/all-out flow is one of the most effective ways to reduce disease pressure. Even in small groups, keeping age groups separate when possible and avoiding frequent mixing can help reduce spread.
Vaccination can be an important tool, especially in herds with known exposure risk. However, vaccines for Mycoplasma hyopneumoniae generally reduce clinical signs and lung lesions rather than fully preventing infection. That means vaccination works best as part of a broader plan, not as a stand-alone fix.
Regular observation is also prevention. If you notice coughing, slower growth, or repeated respiratory flare-ups, involve your vet early. Catching a herd pattern sooner can help limit losses, improve comfort, and guide practical next steps that fit your goals and budget.