Selenium is a highly toxic mineral but it is required in very minute amounts for normal bodily functions. Selenium poisoning is rare and usually occurs when selenium supplement has been wrongly mixed into the ration. Levels above 3ppm in the diet have a clinical affect on the pig and when they reach 10ppm severe clinical signs develop. The toxic dose of selenium by injection is approximately 0.8mg/kg. Problems are more likely to occur with a deficiency producing muscle myopathies and mulberry heart disease.

Clinical signs

Pigs become anorexic with loss of hair and separation of hooves at the coronary band. Paralysis of front and hind legs is common. As the disease progresses there is liver and kidney failure and the pigs become toxic.

Diagnosis

The clinical picture of selenium toxicity is characteristic and almost diagnostic. Confirmation is by the identification of abnormal levels in feed, the liver and the kidneys of affected pigs. Levels above 3ppm are diagnostic.

Treatment

• There is no specific treatment.