Vitamin E and selenium

Vitamin E and selenium are essential nutrients for horses, playing a crucial role in muscle  function, immune support, and overall well-being. However, in Northern California, many horses  are at risk of deficiency due to regional soil conditions and limited access to lush green pastures. ​

The primary reason for selenium deficiency in Northern California horses is the naturally low  selenium levels in the soil. This deficiency translates to pasture and hay grown in the region also  lacking adequate selenium. Since horses rely heavily on forage as their primary source of  nutrition, those not supplemented appropriately can develop a deficiency over time. 

Vitamin E deficiency is also common, particularly in horses that do not have access to fresh  pasture. Vitamin E is abundant in green grass, but hay loses most of its vitamin E content during  the drying and storage process. 

Horses deficient in vitamin E and selenium may exhibit: 
• Muscle weakness or stiffness 
• Poor performance and lethargy 
• Difficulty swallowing or abnormal tongue movement (in severe cases)
• Muscle wasting  
• Neurological symptoms such as trembling, incoordination, or difficulty standing  

Testing and Diagnosis: 
If you suspect your horse may be deficient in either nutrient, Starwood can perform blood tests to  measure vitamin E and selenium levels.  

It is recommended to test horses annually, especially those with limited pasture access,  performance horses, broodmares, and growing foals. Horses showing clinical signs should be  tested immediately to guide treatment decisions. 

Management and Supplementation: 
• Selenium Supplementation: Selenium should be supplemented carefully, as excessive  levels can be toxic. Commercial feeds, ration balancers, and selenium-enriched mineral  supplements can help meet requirements. Always consult your veterinarian before adding  selenium to your horse’s diet.
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• Vitamin E Supplementation: For horses with limited access to fresh pasture, vitamin E  supplementation is highly recommended. Natural-source vitamin E (d-alpha-tocopherol)  is more bioavailable than synthetic forms and is often preferred for supplementation. 

Horse owners in Northern California should be proactive in preventing vitamin E and selenium  deficiencies. Regular blood testing, appropriate supplementation, and a well-balanced diet can  help ensure that your horse remains healthy, strong, and ready for work or competition. By  staying informed and taking action, you can help safeguard your horse from the risks associated  with these common nutrient deficiencies. 

A Starwood veterinarian will be able to help determine your horse's individual risk and whether  testing and supplementation are recommended.