Pigs can and do vomit, and unlike some animals, they have the physical ability to do so relatively easily. If your pig is throwing up, the cause could range from something minor like eating too fast or getting into something it shouldn’t have, to serious conditions like a gastrointestinal blockage or infectious disease. A single episode of vomiting after overeating isn’t usually an emergency, but repeated vomiting, especially with lethargy or diarrhea, needs prompt veterinary attention.
Foreign Bodies and Obstruction
This is one of the most common reasons pet pigs vomit. Pigs are natural foragers and rooters, which means they put almost everything in their mouths. Pet pigs living indoors are at particularly high risk of swallowing household objects: rubber bands, small toys, fabric, pieces of packaging, or food raided from unsecured cabinets. When something gets stuck in the digestive tract, it creates a blockage that the body tries to expel.
The signs of a gastrointestinal obstruction include vomiting, lethargy, loss of appetite, reduced or absent bowel movements, and a visibly swollen abdomen. If your pig’s belly seems tight or painful to the touch and they’re also vomiting, that combination is a red flag. Obstructions don’t resolve on their own and typically require veterinary intervention, sometimes surgery. If you suspect your pig swallowed something, don’t wait to see if it passes.
Eating Too Much or Too Fast
Pigs are enthusiastic eaters, and a pig that gorges on a large meal, gets into a bag of feed, or raids the kitchen may vomit simply because it overwhelmed its stomach. This type of vomiting is usually a one-time event. The pig throws up, seems a bit uncomfortable, and then returns to its normal self within a few hours. If your pig got into something it shouldn’t have but is otherwise alert and acting normally after vomiting, monitor closely but don’t panic.
Gastric Ulcers
Stomach ulcers are surprisingly common in pigs. The area around where the esophagus meets the stomach lacks the protective mucus lining that shields the rest of the stomach from digestive acid. When acidic stomach contents splash against this unprotected tissue, ulcers can develop.
The biggest dietary risk factor is finely ground feed, particularly pelleted feed with a particle size under 700 microns. This type of feed moves through the stomach quickly and creates more fluid stomach contents, which means acid reaches that vulnerable area more easily. Skipped meals are another major trigger. When a pig goes without food for an extended period (due to illness, hot weather, or an empty feeder), the stomach contents become more liquid and acidic with no solid food to act as a buffer.
Most pigs raised in confinement systems develop some degree of ulceration in this area, so even pet pigs on commercial feed can be affected. Signs include vomiting (sometimes with dark or bloody material), grinding teeth, poor appetite, and general discomfort. If you suspect ulcers, switching to a coarser feed and ensuring your pig has consistent access to food without long gaps between meals can help.
Toxic Plants
If your pig has access to a yard, garden, or pasture, plant poisoning is a real possibility. Several common landscape plants cause vomiting in pigs.
- Oleander is extremely toxic in all parts, whether fresh or dried, and causes nausea, vomiting, bloody stool, and dangerous cardiac stress.
- Cherry laurel causes abdominal pain and vomiting.
- Snowberry is especially risky for pigs because the roots are the most toxic part, and pigs naturally dig and root around plants. It causes nausea, vomiting, and dizziness.
- Japanese barberry causes mild to moderate digestive upset including nausea, vomiting, and diarrhea.
If your pig free-ranges in an area with ornamental landscaping, audit what’s growing within reach. Pigs will sample almost anything.
Salt Poisoning and Water Deprivation
Salt toxicity in pigs usually isn’t caused by eating too much salt directly. It happens when a pig doesn’t have adequate access to fresh water, allowing sodium levels in the blood to climb. This can occur if a water source freezes, a waterer malfunctions, or a pig is accidentally locked away from its water supply. The rising sodium concentration pulls water out of brain cells, causing them to shrink. This leads to neurological symptoms: stumbling, head pressing, blindness, and seizures.
Ironically, the most dangerous moment can come when water is restored. If a dehydrated pig suddenly drinks a large amount, the rapid shift in sodium levels causes water to rush into brain cells, leading to dangerous swelling. If you discover your pig has been without water for an extended period, reintroduce water gradually in small amounts rather than allowing unlimited access all at once.
Infectious Diseases
Several viral and bacterial infections cause vomiting in pigs, and they tend to come on fast with multiple symptoms.
Transmissible gastroenteritis (TGE) is one of the most well-known. It’s a highly contagious viral disease that affects pigs of all ages, causing both diarrhea and vomiting. The incubation period is very short, just 18 hours to 3 days. In piglets under two weeks old, mortality is high, with most dying within one to two days from rapid dehydration. Pigs older than four weeks generally survive. Adult sows typically show loss of appetite, vomiting, diarrhea, and depression, but recover within 5 to 10 days. If you have multiple pigs and several start vomiting and developing watery diarrhea around the same time, an infectious cause is likely.
Other infections that can cause vomiting include hog cholera (classical swine fever), which also causes constipation and high fever, and swine erysipelas, which may cause vomiting along with skin discoloration and joint swelling. These are more relevant to farm settings but worth knowing about if your pig has had contact with other swine.
Intestinal Parasites
Heavy roundworm infections can occasionally cause a pig to vomit up adult worms. This is uncommon but unmistakable when it happens. If you see worms in the vomit, your pig needs deworming. Regular fecal checks and a parasite prevention schedule can keep this from becoming an issue.
How to Assess Your Pig at Home
After your pig vomits, a quick physical check can help you gauge how serious the situation is. A healthy pig’s rectal temperature ranges from 101.5 to 103.5°F. A temperature above that range suggests infection or inflammation. Heart rate should fall between 70 and 120 beats per minute, and breathing rate between 30 and 50 breaths per minute. Faster rates combined with vomiting may indicate pain, fever, or dehydration.
To check for dehydration, gently pinch and lift the skin on your pig’s belly. If it snaps back flat in under two seconds, hydration is adequate. If the skin stays tented for longer than two seconds, your pig is at least 5% dehydrated, which is clinically significant. You can also check the gums: they should be moist and pink. Sticky, tacky gums are another sign of dehydration. Press a finger against the gum and release. The color should return in under two seconds. Longer than that means blood circulation is compromised.
A pig that vomits once, passes the skin and gum checks, has a normal temperature, and is still interested in food and activity is likely dealing with something minor. A pig that vomits repeatedly, has a distended or painful belly, shows signs of dehydration, or acts unusually lethargic needs veterinary care quickly. Pigs, especially young or small ones, can dehydrate fast once vomiting and diarrhea start together.