Also known as Selenium/Vitamin E deficiency, or nutritional muscular dystrophy, it is caused by a low level of Selenium/Vitamin E (<1.1 ppm) in the blood resulting from a dietary deficiency due to low soil concentrations.
WMD is most commonly seen in offspring of animals grazed on pasture or fed crops grown from soil which is deficient in selenium. Cattle are normally affected between birth and 4 months of age, with sheep seen to be affected between 3 and 8 weeks of age, it has also been seen in foals up to 12 months of age.
Selenium and Vitamin E act as natural antioxidants, protecting cells of the body against damage, the most vulnerable to damage are skeletal, cardiac and respiratory muscles.
- Pastures deficient in Selenium
- Hay / Silage or grains from soils deficient in Selenium
- Feeds high in polyunsaturated fatty acids, copper or vitamin A can make Vitamin E less bioavailable
- Still births
- Weak calves that die a few days after birth
Delayed onset (following turnout):
- Skeletal muscle - sudden onset stiffness and inability to stand
- Cardiac muscle - sudden death
- Respiratory muscle - respiratory distress
- Intramuscular injection of Potassium Selenate, combined with Vitamin E
- Response to treatment may take a few days
- Oral boluses
- Supplement with sodium selenate orally (however intake can be variable and unreliable)
- Subcutaneous injections
- Oral drenching