How Much Selenium Does Your Horse Need?

Selenium logo

Image via Wikipedia

This question occurred to me this morning as I was getting ready to go out and feed this morning. I know that selenium is a necessary trace mineral and should be part of every horse‘s diet, but how much is too much? Are there symptoms of too much selenium? What happens if my horse isn’t getting the correct amount of it?

Well, I’ve always been the type of gal to find out the answers. 🙂

Here’s why selenium is good for your horse:

  • Aids in proper cell growth and function
  • Improves immune system function
  • Encourages healthy thyroid function
English: "Golden girl" – Horses (unk...

Horses used for breeding may need selenium supplements (Image via Wikipedia)

Your horse should get about 3mg of selenium per day. Ensuring that your horse gets enough selenium can prevent a deficiency that can result in one of two muscle diseases, commonly known as “tying up” and “white muscle disease.”  Selenium can be obtained from hay, grain, pasture, or supplements. However, it is important that the amount of selenium per day does not exceed 3mg.

So now we know why selenium is necessary, especially in horses used for breeding or athletic purposes. But that doesn’t mean we should go and start feeding a supplement right away! Chances are your horse is getting enough selenium from the grain or hay you feed, if not from the pasture itself. It occurs naturally in soil, especially West of the Mississippi River. Also, simply providing a trace mineral block can provide a sufficient amount of selenium. Feeding too much selenium to your horse is toxic and must be avoided.

Signs of selenium toxicity in order of typical occurrence:

Stanleya (plant)

Some plants can accumulate high levels of selenium (Image via Wikipedia)

There are two kinds of selenium toxicity. Acute exposure occurs when a horse ingests a large amount of selenium at once. This may happen if a horse eats a plant that accumulates selenium. Acute exposure symptoms include garlicky breath, muscle tremors, difficultly breathing, and an abnormal gait. Chronic exposure to elevated selenium levels can lead to lameness, blindness, teeth grating, abdominal pain, paralysis, respiratory failure, and death.

If you think your horse may be suffering from selenium deficiency or toxicity, call your vet immediately. Only a licensed veterinarian can determine your horses selenium levels and advise you on whether to add or remove selenium from your horse’s diet.

Selenium is a necessary part of your horse’s diet, but it should be carefully monitored. Do you feed a selenium supplement to any of the horses in your herd?

Related articles


About Genevieve

Genevieve is a southern gal who loves to write. She is a graduate of Everest College with an AAS in Criminal Investigations. Currently, she works as a freelance writer and volunteers for Central Virginia Horse Rescue by writing their monthly newsletter. If she's not writing, you can bet she's either spending time with friends and family, playing with the horses, crafting, or reading. Interested in having a guest blog appearance? Email to get in touch! P.S. Subscribe by RSS feed if you are interested in following her creative insanity... ;)

Posted on January 17, 2012, in Animals, Horses and tagged , , , , , , . Bookmark the permalink. Leave a comment.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: