Equine Selenium

Selenium is an essential micronutrient and is very low in New Zealand soils.

Selenium is an essential constituent of several enzymes, some of which act as antioxidants that protect cells from the waste products of metabolism. In conjunction with vitamin E, selenium is also necessary for effective functioning of the immune system.

Too little selenium results in inadequate levels of antioxidant, leading to tissue damage and a poor immune system - your horse will be stiff and sore after exercise and prone to infections.

Too much selenium interferes with the normal cell protective mechanism and results in severe oxidative tissue damage. Excessive amounts of selenium also disrupt proteins specific to keratin, weakening hair and hoof horn - your horse will suffer loss of mane and tail, weight loss and extreme hoof pain, leading to slippering of the hooves.

There is a delicate balance between too little and too much selenium.

Don't guess, get us to run a simple blood test.

Growing horses are particularly susceptible to the effects of low selenium causing poor growth rates and White Muscle Disease.

Deficiency in adult horses causes muscle-related problems such as “tying up” and a decrease in the efficiency of the immune system, making the horse more susceptible to infections. Most grazing horses in New Zealand that are not hard fed have low blood selenium levels and require supplementation.

Performance horses have high energy demands when they are training and competing. During exercise, muscle cells require antioxidants that need elements such as selenium to deal with free radicals, the byproducts of muscle energy use. The higher the workload the more antioxidants are needed. A horse deficient in selenium is at risk of muscle damage created by free radicals leading to muscle pain and stiffness andi slow muscle recovery following strenuous exercise. Maintaining an adequate supply of selenium is essential in performance horses, but there is a fine line between deficiency and toxicity.

The most common cause of selenium toxicity in New Zealand is either giving  the incorrect dose of a selenium product or the use of several selenium-containing products (eg feed, mineral supplement, oral drench) resulting in an excessive overall dose. Chronic toxicity will cause swelling and pain in the coronary bands which can progress to extreme pain and "slippering" off of the hooves as well as loss of appetite and loss of mane and tail hair.

Don't guess, get us to run a simple blood test - we reccommend this is part of your horse's annual health check.