Salmonellosis in Pigs: Diarrhea, Septicemia, and Food Safety Concerns
- Salmonellosis is a bacterial infection that can cause fever, reduced appetite, yellow to watery diarrhea, dehydration, and sometimes life-threatening septicemia in pigs.
- Weaned and growing pigs are affected most often, but pigs of any age can get sick. Some pigs recover and still shed Salmonella off and on.
- See your vet promptly if your pig has diarrhea plus fever, weakness, dark-red or purple skin discoloration, trouble breathing, or is not drinking.
- Diagnosis usually requires fecal, intestinal, or lymph node culture, and your vet may recommend PCR, bloodwork, or postmortem testing in herd situations.
- Because Salmonella can spread to people and contaminate pork, careful hand hygiene, manure handling, cleaning, and safe cooking are part of treatment and prevention.
What Is Salmonellosis in Pigs?
Salmonellosis is an infection caused by Salmonella bacteria. In pigs, it most often affects the intestinal tract and causes inflammation and tissue damage that lead to diarrhea. Some strains can also move beyond the gut and cause septicemia, meaning the bacteria spread through the bloodstream and affect organs such as the liver and lungs.
Pigs of any age can become infected, but disease is seen most often in weaned and growing-finishing pigs. Common swine-associated strains include Salmonella enterica serotypes Typhimurium, 4,[5],12:i:-, and Choleraesuis. While some pigs become obviously ill, others may carry the bacteria with few signs and shed it intermittently, which matters for both herd health and food safety.
This condition is also a zoonotic concern, which means it can spread from animals to people through feces, contaminated environments, or improperly handled meat. That does not mean every pig with diarrhea has Salmonella, but it does mean diarrhea in pigs deserves careful handling and a conversation with your vet.
Symptoms of Salmonellosis in Pigs
- Fever, often with a sudden drop in appetite
- Yellow to watery diarrhea, sometimes with mucus or shreds of necrotic debris
- Dehydration and sunken appearance
- Lethargy, weakness, or reluctance to stand
- Poor growth or weight loss after weaning
- Recurring bouts of diarrhea over several days
- Blue, purple, or reddened skin discoloration in severe septicemic cases
- Rapid breathing or pneumonia-like signs when infection spreads beyond the gut
- Sudden death in severe septicemia, though this is less common
Mild intestinal cases may look like a short bout of diarrhea with reduced feed intake. More serious cases can progress quickly, especially if fever, dehydration, weakness, or breathing changes are present. Septicemic disease is more urgent because it can affect multiple organs.
See your vet promptly if your pig has diarrhea lasting more than a day, repeated diarrhea episodes, fever, marked weakness, or signs of dehydration. See your vet immediately if your pig is collapsing, not drinking, struggling to breathe, or showing dark skin discoloration.
What Causes Salmonellosis in Pigs?
Salmonellosis develops when a pig is exposed to disease-causing Salmonella bacteria and those bacteria multiply enough to cause intestinal or systemic illness. Important swine strains include S. Typhimurium, S. 4,[5],12:i:-, and S. Choleraesuis. Carrier pigs are a major source of infection, even when they look healthy.
Pigs usually become infected through the fecal-oral route. That can happen from contaminated pens, feeders, waterers, transport equipment, boots, or manure. Rodents, birds, contaminated feed, and contaminated premises can also help spread the organism. Stressors such as weaning, crowding, transport, mixing groups, poor sanitation, or concurrent disease may increase the chance that exposure turns into clinical illness.
In some pigs, the infection stays mostly in the intestines and causes diarrhea. In others, especially with certain serotypes such as S. Choleraesuis, the bacteria may spread through the bloodstream and cause septicemia, hepatitis, or pneumonia. Your vet can help sort out whether Salmonella is the likely cause, because many pig diseases can look similar at first.
How Is Salmonellosis in Pigs Diagnosed?
Diagnosis starts with your vet looking at the full picture: age group affected, recent stressors, fever, diarrhea pattern, and whether multiple pigs are involved. Salmonellosis can resemble other causes of pig diarrhea, including proliferative enteropathy, swine dysentery, coccidiosis, enteric colibacillosis, and dietary or management problems, so testing matters.
The most useful confirmatory tests are usually bacterial culture and serotyping. Your vet may collect feces, intestinal samples, or mesenteric lymph nodes. Merck notes that lymph node culture can be more specific for disease-causing enteric strains than fecal culture alone. PCR is increasingly available and may shorten the time to an etiologic diagnosis.
In herd or severe cases, your vet may also recommend bloodwork, necropsy, and histopathology to look for intestinal damage and to distinguish Salmonella from other diseases. One challenge is that fecal cultures can miss carriers because shedding may be intermittent, so repeat sampling may be needed when carrier status is a concern.
Treatment Options for Salmonellosis in Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm call or clinic exam
- Isolation of sick pig(s)
- Hydration support and oral electrolytes if appropriate
- Temperature and manure monitoring
- Basic fecal testing or initial culture submission
- Targeted sanitation and manure-control plan
- Discussion of human safety precautions for handlers
Recommended Standard Treatment
- Exam and herd-history review
- Fecal or tissue culture with susceptibility testing
- PCR when available
- Prescription antimicrobials selected by your vet based on likely organism and test results
- Injectable treatment for acutely ill pigs when needed
- Water or feed medication plan for affected group when appropriate
- Fluid therapy, anti-inflammatory support, and recheck testing as advised
- Cleaning, disinfection, and source investigation for feed, water, rodents, and traffic flow
Advanced / Critical Care
- Urgent hospitalization or intensive on-farm care
- IV or aggressive fluid support
- Bloodwork and additional monitoring
- Culture, PCR, and expanded diagnostics for coinfections or septicemia
- Parenteral antimicrobials and supportive care directed by your vet
- Necropsy and histopathology in herd outbreaks or deaths
- Vaccination planning for herd-level prevention where appropriate
- Biosecurity overhaul with environmental testing and slaughter-risk discussion
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Salmonellosis in Pigs
Bring these questions to your vet appointment to get the most out of your visit.
- What signs make you most concerned about intestinal disease versus septicemia in my pig?
- Which tests do you recommend first—culture, PCR, bloodwork, or something else—and why?
- Should we test feces, intestinal tissue, or lymph nodes to improve the chance of a clear diagnosis?
- Does my pig need fluids, injectable medication, or hospitalization right now?
- If antibiotics are considered, how will culture or susceptibility results affect that plan?
- How should I isolate this pig and clean the pen to lower spread to other pigs?
- What steps should my household take to reduce Salmonella risk for children, older adults, pregnant people, or anyone immunocompromised?
- If this pig recovers, is there still a risk of intermittent shedding or food safety concerns later on?
How to Prevent Salmonellosis in Pigs
Prevention focuses on lowering exposure and lowering stress. Good manure management, regular cleaning and disinfection, rodent control, clean feed storage, and clean water systems all matter. Avoid overcrowding, reduce unnecessary mixing of pigs, and pay close attention during weaning, transport, and other stressful periods, because those are common times for outbreaks to show up.
Work with your vet on a herd or household biosecurity plan. That may include isolating new arrivals, reviewing traffic flow for boots and equipment, and considering live avirulent vaccination in settings where your vet feels it is appropriate for strains such as S. Choleraesuis or S. Typhimurium. Vaccination is not a substitute for sanitation, but it may help reduce disease and shedding in some situations.
Because Salmonella is a food safety and human health concern, wash hands well after handling pigs, manure, bedding, or feed buckets. Keep pig areas separate from food-prep spaces. If pork from any pig is entering the food chain, follow USDA food safety guidance: cook whole cuts of pork to 145°F (62.8°C) with a 3-minute rest, and cook ground pork to 160°F (71.1°C). If anyone in the home is very young, elderly, pregnant, or immunocompromised, use extra caution and discuss risk reduction with your vet.