Heavy breathing in pigs can signal anything from simple overheating to a serious respiratory infection. A pig’s normal resting respiratory rate is 32 to 58 breaths per minute, so the first step is counting breaths while your pig is calm and comparing to that baseline. If your pig is breathing faster than usual, using its belly to push air, holding its mouth open, or stretching its neck forward, something is wrong and you need to figure out the cause quickly.
Heat Stress Is the Most Common Cause
Pigs are terrible at cooling themselves. They have very few functional sweat glands, which means they rely almost entirely on their environment to regulate body temperature. Mature pigs are most comfortable between 50 and 75°F. Once the air temperature climbs above 80°F, any pig over 100 pounds can rapidly move into life-threatening heat stress. That includes adult potbellied pigs, breeding sows, and grow-finish hogs.
A heat-stressed pig breathes rapidly, pants with its mouth open, becomes lethargic, and may drool excessively or refuse food. If your pig is heavy breathing on a warm day, especially in direct sunlight or a poorly ventilated space, heat is the most likely explanation. Move the pig to shade or a cooler area immediately. Effective cooling methods include sprinkling water directly on the pig’s skin, placing a fan to increase airflow, providing a shallow wallow or mud pit, and offering cool (not ice-cold) drinking water. Misting systems, evaporative cooling pads, and cool concrete floors all help in barn settings. Avoid dumping cold water on an overheated pig suddenly, as the shock can cause additional stress.
Respiratory Infections
If the weather isn’t hot and your pig is still breathing hard, infection moves to the top of the list. Pigs are vulnerable to a group of respiratory illnesses caused by viruses and bacteria that often overlap, making the problem worse than any single pathogen alone.
Swine influenza causes a sudden onset of labored breathing, high fever, a harsh barking cough, and extreme fatigue. Pigs often breathe with visible abdominal effort, using their belly muscles to force air in and out. Most pigs survive swine flu, but they look and sound terrible for several days.
A more chronic pattern, where your pig has a lingering dry cough that gradually gets worse over weeks, often points to a bacterial lung infection called enzootic pneumonia. The cough is nonproductive (nothing comes up), and the pig may seem mostly fine between coughing fits early on, but breathing becomes increasingly labored as the infection progresses.
PRRS virus is particularly dangerous for young pigs and piglets. Signs include high fever, rapid shallow breathing, red or watery eyes, poor appetite, and failure to gain weight. In grow-finish pigs, PRRS can range from barely noticeable to fatal pneumonia depending on the viral strain and whether other infections pile on.
With any respiratory infection, you’ll typically notice additional signs beyond just heavy breathing: fever (a pig’s normal temperature is around 101.5 to 103.5°F rectally), coughing, nasal discharge, reduced appetite, or general listlessness. A pig that is breathing hard and also off its food and running a fever needs veterinary attention promptly.
Lungworm Infection
Pigs that root outdoors or have contact with earthworms can pick up lungworms, parasites that take up residence in the airways. The main sign is a persistent cough that gets worse with exercise. In early stages, you’ll notice rapid, shallow breathing along with occasional coughing. As the infection worsens, pigs may stand with their heads stretched forward and mouths open, drooling, clearly struggling to get air.
Lungworm is diagnosed by testing a fecal sample for larvae. It’s treatable with deworming medication, but heavy infections can cause lasting lung damage, so catching it early matters. Pigs that spend time on pasture or in wooded areas are at higher risk.
Poor Air Quality Indoors
If your pig lives in a barn, shed, or enclosed space, ammonia buildup from urine and manure can directly irritate and damage the respiratory lining. Ammonia levels as low as 50 parts per million cause coughing, eye irritation, and nasal discharge within just a few hours. The current safety threshold is 25 ppm, but research suggests keeping levels below 10 ppm to truly protect pig (and human) respiratory health.
You can often smell ammonia yourself when you enter the space. If the air stings your eyes or nose, your pig is breathing it constantly. Improve ventilation, clean bedding more frequently, and ensure airflow moves at floor level where ammonia concentrates. Dust from feed and dried manure also contributes to chronic respiratory irritation.
Heart Problems in Pet Pigs
Potbellied pigs and other pet breeds are prone to obesity, which puts extra strain on the heart and lungs. Heart failure in pigs looks similar to what it does in other animals: labored breathing, a swollen or distended belly, reduced appetite, extreme tiredness, and occasionally fainting episodes. A veterinarian may detect a heart murmur on examination. Heart-related breathing problems tend to develop gradually and worsen over time rather than appearing suddenly.
If your pig is overweight and increasingly winded during normal activity, or breathes heavily even while resting in a cool environment, a cardiac issue is worth investigating.
Choking or Airway Obstruction
A pig that was fine one moment and suddenly can’t breathe, is gagging, making unusual noises, or pawing at its mouth may have something lodged in its throat. This looks very different from the other causes on this list because it comes on instantly. The pig may cough forcefully, drool, and show obvious panic. Skin and gums may turn blue if the airway is significantly blocked. This is an emergency requiring immediate help.
Warning Signs That Need Urgent Care
Some patterns of heavy breathing are more dangerous than others. Get veterinary help quickly if your pig shows any of the following:
- Blue or purple gums, ears, or skin: this means your pig isn’t getting enough oxygen
- Open-mouth breathing with neck stretched forward: the pig is working hard to get air past an obstruction or through severely damaged lungs
- Belly breathing with visible abdominal pumping: the pig is using every muscle it has to breathe, a sign of significant respiratory distress
- Collapse or fainting: whether from heat, heart failure, or severe infection, a pig that goes down needs immediate intervention
- Breathing hard plus fever plus not eating: this combination strongly suggests infection
Narrowing Down the Cause
Start with context. Check the temperature and humidity where your pig is living. Feel your pig’s ears and skin for unusual warmth, which suggests fever. Listen for coughing, and note whether it’s dry or wet, occasional or constant. Look at how long the heavy breathing has been going on: sudden onset points toward heat, choking, or acute infection, while a gradual worsening over days or weeks suggests chronic infection, lungworm, or heart disease.
A pig that only breathes hard after exertion or in warm weather but is otherwise eating, drinking, and acting normally may just need better cooling and a weight check. A pig that breathes hard at rest, especially with other symptoms, has something more significant going on. Count the resting breaths per minute and note any other changes to share with your vet, as this information helps narrow down the cause faster than a general description of “breathing heavy.”