Like us, horses require a number of different minerals in order to maintain good health. Though many minerals are provided in grass, hay, and feeds, magnesium is one you might want to consider supplementing, especially in spring when fast-growing grasses become depleted of this mineral.
Magnesium is involved in many different functions in the body: It’s an essential component of bones and teeth. In fact, up to 60% of the body’s magnesium is found in the skeletal system, but only 30% of that is available to be used by other parts of the body, when needed. Magnesium works alongside calcium in nerve transmission and muscle function. Additionally, magnesium protects against inflammation and free-radical damage in the body.
For horses with Equine Metabolic Syndrome (EMS) or insulin resistance (IR), adequate magnesium levels are vital for normal secretion of insulin and uptake of glucose. Magnesium can help break down the fatty deposits these horses often develop along the neckline (cresty neck) or rump.
Balance is important with all minerals, and magnesium needs to be balanced with calcium since they compete with each other for absorption. As stated above, these two minerals work together in the muscles—calcium, in charge of muscle contraction and magnesium helping with muscle relaxation. Horses typically need a calcium to magnesium ratio of anywhere between 2-3:1; however, IR and EMS horses may benefit from a ratio as high as a 1:1.
If your horse displays any of the following symptoms, he may be in need of more magnesium:
- irritability;
- hypersensitivity (when being brushed, saddled, or even touched);
- unable to relax, physically or mentally;
- muscle twitching or spasms;
- doesn’t tolerate long periods of work;
- difficulty with collection;
- history of tying up;
- excessive spookiness;
- painful heat in mares;
- teeth grinding;
- irregular heartbeat or pounding heart;
- anxiety/ nervousness; and/or
- gait disturbances.
Horses in hard work or under stress will use up more of their magnesium stores and therefore need supplementation. Magnesium can be lost through sweat and urine, and horses deficient in magnesium may crave salt, leading them to excessively lick salt blocks. Calcium-rich diets (such as those high in alfalfa) can easily create a calcium-magnesium imbalance, necessitating magnesium supplementation as well.
The good news is that magnesium is easy and affordable to supplement, and toxicity situations are rare.


Our Super-Mag Pro Powder was rated as the best magnesium supplement by Horse Journal. It comes as a 4-pound bag and contains 100% Magnesium Proteinate.
Additionally, flaxseed is not only a great source of Omega-3’s, but it’s also high in magnesium, with one cup containing 658 mg of magnesium. Our Organic Flaxseed is ground just prior to shipping to ensure maximum potency and freshness.
We encourage you to take a look at your horse’s diet, and determine if magnesium supplementation might be needed. It may make a big difference in your horse’s health and attitude!
Sources
Sources of Magnesium Including Whole Foods
Supplemental Magnesium for Horses
