Swine Erysipelas in Pigs: Diamond Skin Disease, Arthritis, and Septicemia
- Swine erysipelas is a bacterial infection caused mainly by Erysipelothrix rhusiopathiae and can show up as sudden fever, painful movement, septicemia, arthritis, or the classic raised diamond-shaped skin lesions.
- Some pigs are healthy carriers and shed the bacteria in feces or oronasal secretions, so infection can spread even when no pig looks sick.
- Acute cases can become life-threatening quickly. A pig with fever, weakness, purple skin changes, trouble standing, or sudden collapse should be seen by your vet as soon as possible.
- Early treatment often includes injectable antibiotics and supportive care. Chronic arthritis or heart valve disease can be much harder to reverse, even after the infection is controlled.
- Typical 2025-2026 US cost range for exam, diagnostics, and initial treatment is about $150-$700 for an uncomplicated case, while severe or hospitalized cases may reach $800-$2,500+.
What Is Swine Erysipelas in Pigs?
Swine erysipelas is an infectious bacterial disease of pigs caused mainly by Erysipelothrix rhusiopathiae. It is often called diamond skin disease because some pigs develop raised, firm, pink-to-purple skin patches with a rhomboid or diamond shape. The disease can also cause septicemia, fever, joint pain, arthritis, and in chronic cases, heart valve infection called endocarditis.
This disease can look very different from one pig to another. Some pigs die suddenly with very few warning signs. Others show fever, poor appetite, stiffness, or skin discoloration. Still others survive the early infection but later develop swollen joints, chronic lameness, or heart-related weakness. That wide range is one reason a prompt veterinary exam matters.
Many pigs carry the bacteria in their tonsils without appearing ill. Stress, crowding, transport, heat, or other immune challenges can make disease more likely to surface. Because healthy carriers can shed the organism, erysipelas can appear even in groups that seemed well managed.
There is also a human health angle. Erysipelothrix rhusiopathiae is zoonotic, meaning it can infect people, usually through cuts or skin punctures during handling. If your pig may have erysipelas, use gloves, wash hands well, and follow your vet's biosecurity advice.
Symptoms of Swine Erysipelas in Pigs
- Fever, often 104-108 F
- Sudden loss of appetite or marked depression
- Stiff gait, toe-walking, reluctance to stand, or shifting weight from limb to limb
- Pain when handled, squealing, or lying down quickly after standing
- Red, purple, or raised diamond-shaped skin lesions, especially over the back and sides
- Purplish discoloration of the ears, snout, or abdomen
- Thirst and seeking cool, wet areas
- Swollen joints, chronic lameness, or reduced mobility
- Weakness, breathing difficulty, cyanosis, or collapse from heart involvement
- Sudden death with few or no earlier signs
Call your vet promptly if your pig has fever, stops eating, seems painful, or develops unusual red or purple skin patches. The classic diamond lesions are strongly suggestive of erysipelas, but other serious diseases can look similar, so your vet needs to sort that out.
See your vet immediately if your pig cannot stand, is breathing hard, collapses, has widespread skin discoloration, or if more than one pig in the group becomes sick. Chronic lameness or enlarged joints also deserve attention, because long-term joint and heart damage can follow even after the initial infection seems to pass.
What Causes Swine Erysipelas in Pigs?
Swine erysipelas is caused mainly by the bacterium Erysipelothrix rhusiopathiae. Many pigs carry this organism in their tonsils and may look completely healthy. Those carrier pigs can shed bacteria in feces and oronasal secretions, which helps explain why the disease can spread quietly before obvious illness appears.
Pigs usually become infected by swallowing contaminated feed, water, or fecal material, or through skin abrasions. The organism can persist in the environment for extended periods, including in feces, so sanitation and traffic control matter. On farms or in multi-pig settings, contaminated pens, equipment, boots, and handling areas can all contribute.
Stress often plays a major role in whether exposure turns into disease. Heat stress, transport, crowding, mixing pigs, poor ventilation, and other illness can increase risk. VCA also notes that unvaccinated young pigs may break with disease around 4-12 months of age, especially during stressful periods.
Recovered pigs and chronically infected pigs may continue to act as carriers. That means control is not only about treating the sick pig in front of you. It often involves looking at vaccination status, sanitation, isolation, and the health plan for the whole group with your vet.
How Is Swine Erysipelas in Pigs Diagnosed?
Your vet will start with the history and physical exam. Fever, stiffness, painful joints, sudden illness, and especially raised diamond-shaped skin lesions can make erysipelas a strong concern. Still, your vet may need to rule out other serious causes of septicemia, skin lesions, or lameness in pigs.
Definitive diagnosis usually relies on finding the organism or its DNA. Merck Veterinary Manual notes that diagnosis may be based on bacterial culture from fresh tissues, blood, or fluid, and on PCR testing to detect bacterial DNA. In some cases, tissue testing after death or biopsy can help confirm chronic disease.
A rapid improvement after starting penicillin can support the diagnosis in acute cases, but response to treatment alone is not enough to identify every case. Chronic erysipelas is often harder to confirm because arthritis and endocarditis can persist after the initial bloodstream infection has passed.
Your vet may also recommend bloodwork, joint fluid evaluation, or necropsy of a deceased pig if multiple pigs are affected. Those steps help guide treatment, protect the rest of the group, and reduce the chance of missing another contagious disease that can mimic erysipelas.
Treatment Options for Swine Erysipelas in Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm or clinic exam with isolation and biosecurity guidance
- Presumptive treatment based on exam findings and herd history
- Injectable penicillin or another vet-selected antibiotic for acute disease
- Basic anti-inflammatory or fever control if your vet feels it is appropriate
- Monitoring appetite, temperature, hydration, and mobility at home
Recommended Standard Treatment
- Full veterinary exam and treatment plan
- Targeted diagnostics such as blood sample, PCR or culture submission, and basic lab work as available
- Injectable antibiotic therapy, commonly penicillin-class treatment in acute cases
- Pain and fever management, hydration support, and nursing care
- Recheck exam and herd-level recommendations for isolation, sanitation, and vaccination timing
Advanced / Critical Care
- Emergency or intensive veterinary assessment
- Hospitalization for IV or aggressive fluid support, repeated injections, and close monitoring
- Expanded diagnostics such as CBC, chemistry, PCR or culture, joint evaluation, imaging, or necropsy of affected herd mates when indicated
- Management of severe pain, recumbency, dehydration, or suspected heart involvement
- Detailed herd outbreak plan including quarantine, sanitation review, and vaccination strategy with your vet
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Swine Erysipelas in Pigs
Bring these questions to your vet appointment to get the most out of your visit.
- Do my pig's signs fit acute erysipelas, chronic erysipelas, or another disease that looks similar?
- Which tests are most useful in this case, and will antibiotics affect the results if we start treatment now?
- Is my pig stable for home care, or do you recommend hospitalization or more intensive monitoring?
- What treatment options do you recommend at a conservative, standard, and advanced level of care?
- What cost range should I expect for the exam, testing, medications, and rechecks?
- How do I isolate this pig safely and reduce spread to other pigs on the property?
- When should the rest of the group be examined, treated, or vaccinated?
- What signs would mean the infection may be affecting the joints or heart?
- Is there any zoonotic risk for my family, and what protective steps should we take while handling this pig?
How to Prevent Swine Erysipelas in Pigs
Vaccination is one of the most effective tools for preventing swine erysipelas. Merck Veterinary Manual reports that vaccination is very effective for controlling outbreaks, although it may not prevent every chronic arthritis case. Vaccine timing depends on age, exposure risk, and whether your pig is part of a larger group, so your vet should tailor the schedule.
Merck notes that susceptible pigs may be vaccinated before weaning, at weaning, or several weeks after weaning, with boosters for animals entering the breeding herd and twice-yearly vaccination for breeding stock. VCA also advises vaccination of young pigs with annual boosters for mini-pigs. Your vet can help decide what makes sense for a pet pig versus a breeding or group setting.
Good sanitation matters too. Clean housing, dry bedding, careful manure management, and limiting contamination of feed and water all help reduce exposure. Quarantine new or sick pigs, avoid unnecessary mixing, and reduce stress from transport, crowding, and heat whenever possible.
Do not vaccinate pigs that are actively being treated with antimicrobials unless your vet specifically directs you to do so. Merck warns that antimicrobials can interfere with the immune response to vaccination. If one pig becomes ill, ask your vet about a whole-group prevention plan, because healthy carriers can keep the bacteria circulating.