Magnesium deficiency in horses is quite common but might not be the first thing to be thought of when the horse has hard muscles, is stressed or overly reactive to things in the environment.

The increasing number of horses suffering from magnesium deficiency can be ascribed increasingly depleted farmland which gives a lower natural level of magnesium in the forage and a too low daily ration in relationship to actual need. Another case is an incorrect balance between Calcium, Phosphorus and magnesium where too much Calcium and Phosphorus in relationship to magnesium will have a negative effect on the uptake of magnesium.

The daily need of Magnesium for horses

The horse’s body consists of about 0.05% of magnesium, of this about 60% is found in the skeleton and 30% in the muscles. The daily dose of an adult horse should not be smaller than 1.5 g per 100 kilograms body weight according to the Swedish University of Agriculture Sciences (SLU). The daily loss of magnesium via feces and urine is about 0.6 g per 100 kg body weight. Something that is crucial to consider is that horses that sweats will have a higher daily loss as, because magnesium, like salt, is lost through perspiration. This loss will need to be accounted for in order to meet the daily need.

The amount magnesium of maintenance needed, of course, looks different for young horses, pregnant and lactation mares and so on. SLU has good Swedish guidelines for how the daily dose of should be adjusted to meet the daily need. There is also plenty of reliable sources for this out there in English.  If you are unsure how much magnesium your horse needs, we advise you to talk to your veterinarian.

The importance of magnesium for horses

As for all mammals, magnesium is an important mineral for many functions in the horse’s body. Magnesium affects about 300 enzyme systems in the body. Which is important for the metabolism and signal transfer between cells. Magnesium also acts as a stabilizer in DNA, protein and membrane. As most people know, Magnesium together with Calcium and Phosphorus is important for skeletal formation.

The horse’s muscles contain a lot of intracellular magnesium and Magnesium is crucial for the function and energy usage of the muscles, so also for the heart muscle. Following initial research at SLU, it is suspected that magnesium affects the elasticity of the blood vessel’s  and that magnesium deficiency may increase the risk of rupture of large blood vessel and death. There are also studies indicating that magnesium deficiency can lead to changes in blood circulation.

Symptoms of Magnesium deficiency in horses

With an excising Magnesium deficiency it’s difficult for the body to handle the substances released by stress and/or fear, thus adding magnesium may have a calming effect on the horse. An important sign of a deficiency is that the horse is abnormally nervous, stressed and/or have excessive reaction to things in the environment. In the case of magnesium deficiency, it is also common with tense and hard muscles that are not a result of ill fitting equipment.

Symptoms of more severe magnesium deficiency are an inability to relax the muscles after work, muscle tremors and ataxia. In very far-reaching cases, magnesium deficiency may lead to collapse and sudden death but this is unusual.

Do you suspect that your horse has magnesium deficiency? We produce a high quality magnesium supplement called Sedipro. Sedipro consists of a unique combination of bio-available magnesium in the form of magnesium chelate and magnesium oxide. Sedipro also contains L-tryptophan, Passion flower and Griffonia that together with magnesium supports a balanced and harmonious temperament.