Sheep Selenium and Vitamin E Deficiency White Muscle Disease

White muscle disease — nutritional muscular dystrophy from selenium or vitamin E deficiency — causes skeletal and cardiac muscle degeneration in young lambs, resulting in weakness, recumbency, and death if untreated. Prevention through maternal supplementation is simple and highly effective.

Key Facts

White muscle disease affects lambs most severely in the first few weeks of life, when rapid muscle growth outstrips selenium supply
Cardiac and skeletal muscle degeneration are distinct syndromes — cardiac forms cause sudden death; skeletal forms cause progressive weakness and recumbency
Selenium deficiency is common in areas with volcanic, sandy, or highly leached soils, and is compounded by high sulphur intake from fertilisers
Vitamin E acts synergistically with selenium in protecting cell membranes from oxidative damage — deficiency of either can cause the condition independently
Injectable selenium and vitamin E given to ewes four weeks before lambing prevents almost all cases of perinatal white muscle disease

Welfare Considerations

Lambs with white muscle disease experience progressive muscular pain and weakness, manifesting as reluctance to suckle, inability to keep pace with the ewe, and eventual recumbency from which they cannot rise. Cardiac cases die suddenly without the prolonged suffering of the skeletal form, but skeletal cases may lie unable to move for hours to days before receiving treatment or dying. Prevention is both effective and economical. Welfare-centred flocks assess soil and forage selenium status annually, supplement pregnant ewes before lambing in deficient areas, and treat affected lambs promptly with injectable sodium selenite under veterinary supervision.

What You Can Do

Test soil and forage selenium levels in areas with a history of white muscle disease before supplementing ewes in late pregnancy
Supplement pregnant ewes with selenium and vitamin E injection four to six weeks before lambing in confirmed deficient areas
Check blood selenium levels in ewes before the mating season to confirm deficiency and target supplementation accurately
Treat affected lambs promptly with injectable selenium under veterinary guidance — delay significantly worsens prognosis
Never exceed recommended selenium supplementation doses — selenium toxicity in sheep causes sudden death at doses only marginally above therapeutic levels