Interstitial Pneumonia in Pigs

Quick Answer
  • Interstitial pneumonia is inflammation that affects the lung tissue itself, not only the airways. In pigs, it is often linked to viral disease such as PRRS or PCV2, sometimes with secondary infections.
  • Common signs include rapid breathing, increased effort to breathe, a 'thumping' breathing pattern, lethargy, poor appetite, fever, and slower weight gain.
  • See your vet immediately if your pig is open-mouth breathing, has blue or gray gums, cannot stand comfortably, or seems suddenly weak.
  • Diagnosis usually needs a physical exam plus testing such as PCR, bloodwork, imaging, or samples from the respiratory tract. In herd situations, your vet may also recommend necropsy and lab testing on affected pigs.
  • Typical U.S. veterinary cost range in 2025-2026 is about $150-$500 for an exam and basic workup for one pet pig, while hospitalization, oxygen support, imaging, and advanced testing can raise costs to $800-$2,500+.
Estimated cost: $150–$2,500

What Is Interstitial Pneumonia in Pigs?

Interstitial pneumonia is a pattern of lung disease where inflammation affects the delicate tissues around the air sacs. That matters because these tissues help move oxygen into the bloodstream. When they become thickened, swollen, or damaged, pigs can breathe faster and work much harder to get enough air.

In pigs, interstitial pneumonia is not one single disease. It is a lung change your vet may suspect from clinical signs, imaging, or lab results, and it can be associated with several underlying problems. Important causes include viral infections such as porcine reproductive and respiratory syndrome (PRRS) and porcine circovirus type 2 (PCV2). Some pigs also have mixed respiratory disease, where viruses, bacteria, environment, and stress all play a role.

Pet pigs and small hobby pigs can become very sick from pneumonia because respiratory disease can progress quickly. Even when the first signs look mild, worsening effort to breathe, weakness, or reduced appetite should be taken seriously. Your vet can help determine whether this is a manageable respiratory infection, a more severe lung injury pattern, or part of a larger herd health problem.

Symptoms of Interstitial Pneumonia in Pigs

  • Rapid breathing at rest
  • Increased effort to breathe, including abdominal push or flared nostrils
  • Thumping or heaving breathing pattern
  • Lethargy, weakness, or reluctance to move
  • Poor appetite or reduced nursing in piglets
  • Fever
  • Poor growth or weight loss
  • Coughing may be present, but some pigs mainly show breathing effort rather than a strong cough
  • Blue, gray, or very pale gums
  • Collapse, inability to stand, or sudden death

Some pigs with interstitial lung disease look mildly tired at first, then worsen over hours to a day. That is why breathing changes matter more than cough alone. A pig that is breathing faster, stretching its neck, using its belly to breathe, or refusing food needs prompt veterinary attention.

See your vet immediately if your pig has open-mouth breathing, blue or gray gums, marked weakness, or severe distress. In young piglets, a pronounced thumping breathing pattern is especially concerning.

What Causes Interstitial Pneumonia in Pigs?

Interstitial pneumonia in pigs is most often associated with infectious disease. PRRS can cause severe interstitial pneumonia, especially in young pigs, and it also weakens normal immune defenses, making secondary infections more likely. PCV2-associated disease can also produce interstitial to bronchointerstitial lung lesions, often along with weight loss, enlarged lymph nodes, and poor growth.

Other respiratory pathogens may contribute to a mixed picture. Influenza A virus in swine can cause acute respiratory disease, and Mycoplasma hyopneumoniae is a major part of the porcine respiratory disease complex. While mycoplasma more often causes a chronic airway-centered pneumonia pattern, coinfections can make lung disease more severe and less predictable.

Noninfectious factors can make things worse even when a virus starts the problem. Poor ventilation, dust, ammonia buildup, crowding, transport stress, temperature swings, and weak biosecurity all increase respiratory strain and disease spread. In herd settings, your vet may look beyond one pig and assess housing, airflow, sanitation, vaccination history, and recent animal movement.

How Is Interstitial Pneumonia in Pigs Diagnosed?

Your vet starts with a history and physical exam, paying close attention to breathing rate, breathing effort, temperature, hydration, appetite, and oxygenation. They may ask about recent new pigs, show exposure, contact with other swine, vaccination status, and whether multiple pigs are affected.

Testing depends on how sick the pig is and whether this is a single pet pig or part of a group. Common options include bloodwork, pulse oximetry if available, chest imaging, and PCR testing on nasal, oral, tracheal, or lung-related samples to look for viruses or other pathogens. In herd medicine, sample choice matters, and your vet may recommend testing several pigs rather than only one.

If a pig dies or is euthanized, necropsy with histopathology can be one of the most useful ways to confirm interstitial pneumonia and identify the likely cause. That is especially important when PRRS, PCV2, influenza, or mixed respiratory disease is suspected. Because treatment choices, isolation plans, and prevention steps depend on the underlying cause, diagnosis is about more than confirming 'pneumonia' alone.

Treatment Options for Interstitial Pneumonia in Pigs

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$150–$400
Best for: Stable pigs with mild to moderate signs, pet parents who need a practical starting plan, or situations where immediate hospitalization is not possible.
  • Veterinary exam and basic assessment
  • Isolation from other pigs
  • Supportive care plan for warmth, hydration, easier access to food and water, and reduced stress
  • Targeted medications your vet feels are appropriate for comfort, fever control, or likely secondary bacterial infection
  • Home monitoring instructions for breathing effort, appetite, and activity
Expected outcome: Fair if caught early and the pig is still eating, hydrated, and not in major respiratory distress. Prognosis becomes guarded if breathing effort increases or the underlying disease is viral and severe.
Consider: Lower upfront cost, but fewer diagnostics means more uncertainty about the exact cause. Home care may not be enough if oxygen support or rapid reassessment becomes necessary.
Most Common

Recommended Standard Treatment

$400–$1,200
Best for: Most pigs with ongoing respiratory signs, fever, reduced appetite, poor growth, or suspected infectious pneumonia that needs a clearer diagnosis.
  • Veterinary exam plus a more complete diagnostic workup
  • Bloodwork and selected respiratory testing such as PCR or other lab samples
  • Chest imaging when available and appropriate
  • Prescription treatment plan tailored by your vet, often combining supportive care with medications for secondary infection risk or inflammation management when indicated
  • Short in-clinic observation, fluid support, and recheck planning
Expected outcome: Fair to good in moderate cases when the pig responds within the first 24-72 hours. More guarded if PRRS, PCV2-associated disease, or multiple coinfections are involved.
Consider: Provides better diagnostic clarity and a more targeted plan, but costs more and may still not fully define the cause without advanced sampling or necropsy.

Advanced / Critical Care

$1,200–$3,500
Best for: Pigs with severe breathing effort, blue or gray gums, collapse, dehydration, failure of outpatient care, or outbreaks affecting several pigs.
  • Emergency stabilization and hospitalization
  • Oxygen therapy and close respiratory monitoring
  • Advanced imaging or expanded infectious disease testing
  • Intravenous or intensive fluid support when needed
  • Frequent reassessment for worsening distress, dehydration, or complications
  • Herd-level consultation, necropsy, and biosecurity planning if multiple pigs are affected
Expected outcome: Guarded to poor in critical cases, especially when severe viral lung injury or major coinfection is present. Some pigs recover, but others may have lasting lung damage or die despite treatment.
Consider: Offers the highest level of monitoring and support, but cost range is much higher and outcomes can still be uncertain in severe interstitial lung disease.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Interstitial Pneumonia in Pigs

Bring these questions to your vet appointment to get the most out of your visit.

  1. What are the most likely causes of this lung pattern in my pig?
  2. Does my pig need emergency oxygen support or can care safely start at home?
  3. Which tests are most useful first based on my pig's signs and my budget?
  4. Are PRRS, PCV2, influenza, or mycoplasma concerns in this case?
  5. Should my pig be isolated from other pigs, and for how long?
  6. What changes in breathing or behavior mean I should come back right away?
  7. If this is part of a herd problem, which pigs should be tested and what samples do you recommend?
  8. What prevention steps, vaccines, ventilation changes, or biosecurity updates make the most sense for my situation?

How to Prevent Interstitial Pneumonia in Pigs

Prevention focuses on lowering infectious exposure and reducing lung stress. Good ventilation, lower dust, clean bedding, dry housing, and avoiding overcrowding all help protect the respiratory tract. Sudden temperature changes, ammonia buildup, and transport or mixing stress can make respiratory disease more likely and more severe.

Biosecurity matters. New pigs should be quarantined before joining resident pigs, and pigs returning from fairs or shows should be separated and monitored before re-entry. Limiting contact with outside swine, including feral swine when relevant, also reduces disease risk. Shared equipment, boots, and clothing can spread pathogens between groups.

Vaccination plans can be an important part of prevention, especially for herd situations, but the right program depends on your pig's age, exposure risk, and local disease patterns. Your vet can help you decide whether vaccines for problems such as influenza, PCV2, or other respiratory pathogens fit your situation. If one pig in a group develops pneumonia, early veterinary guidance can help protect the others.

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