Nutritional Myopathy in Pigs: Vitamin E and Selenium Deficiency Muscle Disease

Quick Answer
  • Nutritional myopathy in pigs is a muscle and heart disease linked to low selenium, low vitamin E, or both.
  • Young, fast-growing pigs between about 2 and 16 weeks old are most often affected, and some pigs may die suddenly after stress or exercise.
  • Signs can include weakness, stiff gait, trouble standing, breathing changes, poor growth, and sudden death.
  • Your vet may diagnose it using history, diet review, bloodwork, and sometimes necropsy with tissue testing.
  • Treatment usually focuses on correcting the diet, giving veterinarian-directed selenium and vitamin E supplementation, and reducing stress on affected pigs.
Estimated cost: $150–$1,200

What Is Nutritional Myopathy in Pigs?

Nutritional myopathy is a disease of skeletal muscle and sometimes heart muscle that happens when pigs do not get enough selenium, vitamin E, or both. These nutrients work together as antioxidants. When levels are too low, muscle cells are more likely to be damaged by oxidative stress.

In pigs, this problem is often discussed alongside mulberry heart disease and hepatosis dietetica, because selenium and vitamin E deficiency can contribute to those syndromes. Young, rapidly growing pigs are the group most often affected. In some cases, the first sign is weakness or a stiff gait. In others, a pig may die suddenly with very little warning.

This is not something pet parents should try to diagnose on their own. Muscle weakness, collapse, and sudden death can also happen with infections, toxins, trauma, or other nutritional problems. Your vet can help sort out what is most likely and which care options fit your pig, your goals, and your budget.

Symptoms of Nutritional Myopathy in Pigs

  • Stiff gait or reluctance to move
  • Weakness, trembling, or tiring easily
  • Difficulty standing or sudden collapse
  • Rapid breathing or distress after exercise
  • Poor growth or unthrifty appearance
  • Sudden death, especially in fast-growing young pigs
  • Nervous system signs after surviving an acute episode

See your vet immediately if your pig is weak, cannot rise, seems painful when walking, has breathing changes, or collapses. Sudden death can occur with selenium and vitamin E deficiency syndromes, especially in young pigs under stress. Even milder signs like stiffness or slower growth deserve attention, because early diet correction may help protect other pigs in the group.

What Causes Nutritional Myopathy in Pigs?

The main cause is too little selenium, vitamin E, or both in the diet. Selenium levels in feed ingredients can vary with soil levels, and some parts of the United States are known to have selenium-deficient soils. Vitamin E can also be lost when feed is old, poorly stored, exposed to heat or moisture, or contains rancid fats.

These nutrients protect cell membranes from oxidative damage. When pigs do not get enough, muscle tissue becomes more vulnerable, especially during rapid growth. That is why this condition is seen most often in young, fast-growing pigs, commonly between about 2 and 16 weeks of age.

Other diet factors can raise risk. Low protein intake, low sulfur-containing amino acids, high levels of polyunsaturated fats, mycotoxins, and compounds that interfere with selenium can all make deficiency problems more likely. In nursing piglets with low vitamin E status, iron dextran injections may also trigger severe muscle injury that looks like selenium or vitamin E deficiency. Your vet may want to review the full feeding program, not only one supplement.

How Is Nutritional Myopathy in Pigs Diagnosed?

Diagnosis usually starts with a history and diet review. Your vet will ask about the pigs' age, growth rate, feed source, mineral program, storage conditions, recent stress, and whether multiple pigs are affected. A physical exam may show weakness, stiffness, trouble rising, or signs of cardiovascular stress.

Testing may include bloodwork and targeted nutrient testing. In deficiency cases, selenium, vitamin E, and glutathione peroxidase levels may be low, while muscle enzymes such as CK and AST may be increased. These results can support the diagnosis, but they still need to be interpreted in context.

If a pig dies, necropsy can be one of the most useful and cost-conscious ways to reach an answer for the whole group. Your vet may submit tissues for histopathology to look for characteristic heart and muscle lesions. This also helps rule out other serious causes such as septicemia, edema disease, polyserositis, toxicosis, or porcine stress syndrome.

Treatment Options for Nutritional Myopathy in Pigs

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$150–$350
Best for: Mild cases, early signs in a small group, or situations where the budget is limited but prompt action is still possible.
  • Farm or clinic exam with focused diet and mineral review
  • Basic supportive care plan for affected pigs
  • Immediate feed correction or replacement of suspect feed
  • Veterinarian-directed selenium and vitamin E supplementation for affected pigs or the group when appropriate
  • Reduced handling, transport, and exercise to lower stress
Expected outcome: Fair if caught early and pigs are still standing, eating, and not showing severe heart involvement.
Consider: Lower upfront cost, but less diagnostic confirmation. This approach may miss other diseases that can look similar, and severely affected pigs may worsen quickly.
Most Common

Recommended Standard Treatment

$350–$800
Best for: Most pigs with suspected deficiency where you want a practical balance of confirmation, treatment, and herd protection.
  • Veterinary exam plus full ration and supplement review
  • Bloodwork with muscle enzymes such as CK and AST
  • Selenium and/or vitamin E testing when available
  • Veterinarian-directed injectable or oral selenium/vitamin E support as appropriate
  • Group-level prevention plan for herdmates, including feed reformulation and monitoring
Expected outcome: Fair to good for uncomplicated cases treated early. Guarded if pigs are collapsing, severely weak, or showing likely cardiac damage.
Consider: More complete than conservative care and often the best fit for herd management, but costs more and some nutrient tests may take time or need outside labs.

Advanced / Critical Care

$800–$1,200
Best for: Severe outbreaks, sudden deaths, valuable breeding animals, or cases where ruling out infectious or toxic causes is essential.
  • Urgent veterinary assessment for recumbent, collapsing, or high-value pigs
  • Expanded lab testing and close monitoring
  • Necropsy and histopathology for pigs that die, to confirm diagnosis and guide herd decisions
  • Intensive supportive care such as fluids, assisted feeding, oxygen support if available, and nursing care
  • Detailed herd investigation including feed sourcing, storage review, and prevention protocol for sows and piglets
Expected outcome: Variable. Some pigs recover if treated before major heart or muscle damage occurs, but sudden death can still happen in acute cases.
Consider: Most information and monitoring, but also the highest cost. Intensive care may not change the outcome in pigs with advanced cardiac injury.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Nutritional Myopathy in Pigs

Bring these questions to your vet appointment to get the most out of your visit.

  1. You can ask your vet whether my pig's signs fit selenium deficiency, vitamin E deficiency, or another condition that looks similar.
  2. You can ask your vet which feed, treats, or supplements should be reviewed first for possible nutrient gaps or storage problems.
  3. You can ask your vet whether bloodwork, selenium testing, vitamin E testing, or muscle enzyme testing would be most useful in this case.
  4. You can ask your vet if the other pigs in the group should be examined or supplemented too.
  5. You can ask your vet whether a pig that died should have a necropsy to help protect the rest of the herd.
  6. You can ask your vet what handling changes are safest right now, including exercise restriction, transport delays, and stress reduction.
  7. You can ask your vet what withdrawal times or food-animal medication rules apply before using any injectable selenium or vitamin E product.
  8. You can ask your vet how to build a prevention plan for piglets, growers, and pregnant sows based on your region and feed source.

How to Prevent Nutritional Myopathy in Pigs

Prevention starts with a balanced ration and a reliable vitamin-mineral program. In pigs, selenium and vitamin E need to be considered together. Current veterinary references list a selenium requirement for swine of about 0.10-0.30 mg/kg of diet, and vitamin E requirements of about 11-16 IU/kg for growing pigs and 44 IU/kg for sows. Your vet or a swine nutritionist can help confirm whether your current feed actually meets those needs.

Feed quality matters as much as the label. Vitamin E activity drops when feed is exposed to heat, moisture, rancid fat, organic acids, or long storage. Using fresh feed, rotating inventory, and storing feed in cool, dry conditions can reduce risk. If you mix your own feed, premix accuracy is especially important.

For herds in selenium-deficient regions or with a history of deficiency problems, your vet may recommend a prevention plan for sows late in gestation and for piglets after birth. That plan should be individualized, because too much selenium can also be harmful. The safest approach is to work with your vet before adding injectable products or changing the mineral program.

Find a Vet Near You