The European Agency for the Evaluation of Medicinal Products Veterinary Medicines Evaluation Unit

1. Selenium is an essential micronutrient for both animals and man. Deficiency syndromes such as growth impairment, muscular degeneration, cardiomyopathy, hepatic degeneration and reproduction disturbances in ruminants and non-ruminants as well as exudative diathesis and encephalomalacia in poultry have been well documented. In veterinary medicine there is a widespread prophylactic and therapeutic use of sodium selenite salt, often in combination with vitamin E, against diseases and disorders related to selenium/vitamin E deficiencies. The recommended doses for sodium selenite vary between 0.01 and 0.08 mg Se/kg bw (0.25-1.5 mg/kg feed) for the preparations used in medicated feed in the horse, cow and sheep as well as in swine and poultry. Selenium is also applied as sodium and potassium selenates (0.08-0.24 mg/kg bw). Dosing is given in a single application, divided into 35 daily doses or repeated every two or three weeks. In poultry supplemented feeding for 1-2 weeks with 2-3 week intervals is indicated. Selenium preparations (potassium selenate and sodium selenite) are also used for parenteral application (intramuscular) in cattle, swine and sheep as a single dose of 0.02-0.06 mg Se/kg bw or repeated dosing with a one week interval. A slow-release bolus, indicated in ruminants, gives a daily dose 0.05 mg selenium/kg/day for 120 days. Sodium selenite and sodium selenate have also been approved as feed additives at a maximum concentration of 0.5 mg selenium/kg feed (complete feed). Selenium-based dietary supplements (up to 200 μg selenium/person/day) have a long history of use in human nutrition.