| Scott Fritz, DVM, ABVT Toxicologist Beef Cattle Institute Kansas State University Scottfritz@vet.k-state.edu |
Sources
Calves are usually affected due to dams being deficient in vitamin E and/or selenium during gestation. Selenium is naturally found in grains and forage. However, certain areas of the country such as the northeast, eastern seaboard, and northwest are known to have deficient selenium levels in the soil. Vitamin E is normally found in high-quality hay, silage, and green forage. Supplements containing vitamin E can also be administered. Selenium is legally regulated in feed supplements due to its toxic potential.
Mechanism
Vitamin E and selenium act as antioxidants and protect cells from damage caused by free radicals. Without this protection, heavily oxygen-dependent cells like cardiac and muscle cells are injured or die.
Signs
- Animals with primarily skeletal muscle damage can show an altered gait, muscle weakness, difficulty rising, and pain on palpation.
- Animals with primarily cardiac damage can show respiratory stress, difficulty breathing, and a buildup of fluid in the abdomen due to heart failure.
Treatment
Supportive care is necessary to make sure the animal is stable. Once stable, supplementation of vitamin E/selenium should be administered to the affected animal. Injectable selenium and vitamin E supplements are available for short term use. The diet should be evaluated to make sure appropriate amounts of vitamin E and selenium are present to avoid further deficient animals.
Diagnosis
- Vitamin E serum (red top tube) or fresh/frozen liver
- Selenium whole blood (purple top tube) or fresh/frozen liver; feed samples can also be analyzed
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