Advice article filter
Magnesium: a matter of life or death
Magnesium, together with calcium, plays an important role in the mechanism of the muscles. In simple terms, calcium looks after the tension of the muscles and magnesium looks after the relaxation. It does happen that a horse shows a magnesium deficiency after intensive performance. Such a horse stands on trembling legs and is not able to relax. This is an extreme example that could occur after a stressful experience.
The horse needs magnesium every day. Magnesium cannot, like copper, be stored in the liver as a reserve for temporary deficiencies.
In emergencies, it is fortunate that nature has provided a way the horse can utilise the magnesium built into the bone tissue. Magnesium, calcium and phosphorus are the building blocks of the skeleton. Because old bone is replaced regularly by new bone, the minerals calcium, phosphorus and magnesium are released into the blood for a short time, available for the horse’s body.
That means, in contrast with what people think, the horse’s skeleton is dynamic. It is normal that the horse breaks down a little bit of skeleton every day and replaces it again, releasing temporary reserves.
In case the reserves are used by, for instance, the muscles, then the new bone will contain fewer minerals than the old bone. This process is called demineralisation.
When the horse has had magnesium deficiencies for a long time, the quality of the skeleton will have degraded in quality. That is when injuries can happen more easily.
The whole story is more complicated and more minerals are involved.