White Muscle Disease in Pigs: Selenium Deficiency and Weakness
- White muscle disease is a nutritional muscle disorder linked to selenium deficiency, vitamin E deficiency, or both.
- Young, fast-growing piglets are most at risk, especially when the sow's diet was low in selenium during gestation or lactation.
- Signs can include weakness, stiffness, trouble standing or nursing, rapid breathing, poor growth, and sudden death if the heart muscle is affected.
- See your vet promptly if a piglet is weak, cannot rise, seems painful when moving, or has breathing trouble.
- Early veterinary care may include an exam, diet review, bloodwork, and carefully dosed selenium/vitamin E treatment when your vet feels it is appropriate.
What Is White Muscle Disease in Pigs?
White muscle disease, also called nutritional myopathy or nutritional muscular dystrophy, is a disorder in which muscle tissue is damaged by oxidative injury. In pigs, it is linked to low selenium, low vitamin E, or both. Selenium is usually the more important factor, and deficiency often starts with the sow's diet during pregnancy and nursing.
The condition is considered uncommon in pigs compared with some other species, but it can still be serious. Merck notes that in pigs, selenium and vitamin E deficiency more often affects the heart or liver, and white muscle disease itself is considered rare. Even so, affected piglets, weanlings, and sometimes sows can show weakness, poor movement, or sudden collapse.
The name comes from the pale, streaked appearance damaged muscles can have on necropsy. Those muscles may include skeletal muscles used for standing and walking, and sometimes the heart muscle. When the heart is involved, the disease can progress very quickly.
For pet parents, the key point is this: a weak piglet is not something to watch at home for long. If your pig is struggling to stand, nurse, breathe normally, or keep up with littermates, your vet should be involved right away.
Symptoms of White Muscle Disease in Pigs
- Weakness or inability to rise
- Stiff gait or reluctance to walk
- Muscle tremors or shakiness
- Trouble nursing or poor weight gain
- Rapid breathing or breathing distress
- Sudden collapse or sudden death
- Lethargy and reduced activity
- Pain with movement or exercise intolerance
Some pigs show only vague signs at first, like lagging behind, weakness, or poor growth. Others become stiff, have trouble standing, or seem distressed after exertion. If cardiac muscle is affected, breathing problems, arrhythmias, collapse, or sudden death can occur.
See your vet immediately if your pig has breathing trouble, cannot get up, stops nursing, or suddenly worsens. These signs can overlap with trauma, infection, toxin exposure, iron-related problems, neurologic disease, and other nutritional disorders, so a veterinary exam matters.
What Causes White Muscle Disease in Pigs?
The underlying cause is inadequate antioxidant protection in muscle cells. Selenium is part of important antioxidant enzymes, including glutathione peroxidase, and vitamin E helps protect cell membranes from oxidative damage. When levels are too low, muscle cells are more vulnerable to injury.
In pigs, deficiency often starts with the breeding herd. If a sow eats a selenium-deficient diet during gestation, piglets may be born with low stores. Merck also notes that selenium-deficient soils are common in parts of the northeastern and eastern seaboard and northwestern United States, which can affect feed ingredients grown in those regions.
Vitamin E problems can add to the risk, especially when feed quality is poor or stored in ways that reduce vitamin E content over time. Nursing pigs with selenium and vitamin E deficiency may also be more susceptible to problems after iron injections, and Merck notes that iron dextran can precipitate a severe myopathy in piglets with low vitamin E status.
This is why your vet will usually look beyond the individual pig. Feed source, mineral supplementation, storage conditions, litter history, sow nutrition, and any recent injectable products all help explain why weakness developed.
How Is White Muscle Disease in Pigs Diagnosed?
Diagnosis starts with a hands-on exam and a careful nutrition history. Your vet will ask about the pig's age, growth rate, littermates, sow diet, mineral supplementation, feed brand or formulation, storage conditions, and whether iron injections or other treatments were recently given.
Because weakness in pigs has many possible causes, diagnosis is usually based on a combination of findings rather than one clue alone. Your vet may recommend bloodwork, including selenium and sometimes vitamin E testing, plus muscle enzyme testing when available. Cornell notes that selenium deficiency and vitamin E deficiency do not always occur together, so testing one does not automatically rule in or rule out the other.
In some cases, your vet may make a presumptive diagnosis based on signs, diet review, regional risk, and response to treatment. If a pig dies, necropsy can be very helpful. Pale or streaked skeletal muscle, heart lesions, or other tissue changes may support the diagnosis and help rule out infectious or toxic causes.
Other conditions your vet may consider include trauma, porcine stress syndrome, infectious disease, iron-related toxicosis, congenital weakness, and neurologic disorders. That is one reason home supplementation without guidance is risky. Too little may not help, and too much selenium can be toxic.
Treatment Options for White Muscle Disease in Pigs
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm or clinic exam
- Basic diet and supplement review
- Targeted selenium/vitamin E treatment if your vet recommends it
- Nursing support, warmth, easy access to water and feed
- Activity restriction and close monitoring
Recommended Standard Treatment
- Veterinary exam and full nutrition history
- Bloodwork or targeted mineral testing when available
- Vet-directed selenium/vitamin E therapy
- Supportive care such as fluids, assisted feeding, pain control, and monitoring
- Review of sow and herd supplementation plan to prevent more cases
Advanced / Critical Care
- Emergency assessment for collapse or breathing distress
- Hospitalization or intensive on-farm monitoring
- Expanded diagnostics, ECG or additional testing if cardiac disease is suspected
- Aggressive supportive care for recumbent or critically weak pigs
- Necropsy and herd-level consultation if deaths occur
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About White Muscle Disease in Pigs
Bring these questions to your vet appointment to get the most out of your visit.
- Does my pig's exam fit selenium deficiency, vitamin E deficiency, or another cause of weakness?
- Which tests would be most useful in this case, and which ones are optional if I need a more conservative plan?
- Is this an emergency today, especially if my pig is weak but still standing?
- Should littermates or the sow be evaluated too?
- What feed or mineral changes do you recommend, and how quickly should we make them?
- Is selenium supplementation safe for my pig, and what are the risks of over-supplementing?
- Could recent iron injections or another treatment have made this worse?
- What signs mean I should call back immediately or bring my pig in for urgent care?
How to Prevent White Muscle Disease in Pigs
Prevention focuses on balanced nutrition, especially for breeding animals. Sows need appropriate selenium and vitamin E in the ration during gestation and lactation so piglets are born with better stores. Merck's swine nutrient tables list selenium at 0.15 ppm and vitamin E at 44 IU/kg for gestating and lactating sows, but your vet or a swine nutritionist should help confirm what is appropriate for your specific feed program.
Store feed properly and use it while fresh. Vitamin E can decline in poor-quality or improperly stored feed, so old, oxidized, or poorly protected feed may increase risk. If you mix your own rations or use regional grains and forage, periodic feed analysis can be worthwhile, especially in selenium-deficient areas.
If one piglet is affected, think herd-level prevention. Your vet may recommend reviewing the sow ration, mineral source, injectable product history, and the timing of any supplementation program. This matters because weakness in one piglet can be the first visible sign of a broader nutritional gap.
Do not add selenium products on your own without veterinary guidance. Selenium has a narrow safety margin. The safest prevention plan is a ration and supplement program your vet is comfortable with, matched to your pigs' age, life stage, and local feed conditions.