Magnesium - A calming supplement for excitable Horses

Magnesium can help to calm excitable horses to produce good dressage resultsMany horse owners use equine calming supplements containing magnesium to calm their nervous, excitable, stressed, or spooky horses - especially before competitions or during periods of box rest.

Some of the most popular of these equine feed supplements contain magnesium which is known to calm the nervous and cardio-vascular system and relax the muscles and help to manage frightened or unpredictable behaviour or nervous habits such as headshaking.

Magnesium has been proven to be an effective and legal way to relax and calm a horse before a competition, show or race and is used by National Hunt, flat racing, dressage and show jumping yards.

Riding can be more pleasurable on a calm horseHorse owners who just want a quiet, happier ride out are also benefitting from feeding magnesium as a supplement.

Magnesium has an important part to play part in muscle and nerve and function.

Magnesium can calm the nervous and cardio-vascular systems and induces muscle relaxation.


Horses and ponies that have a deficiency in magnesium may show signs of nervousness, excitability and muscle shaking.

Some horses become especially "fresh" in the springtime. The fast growth rate of grass in spring means that spring grazing has an increased sugar content and is also often deficient in magnesium. As a result many horses become much more excitable, some become almost unrideable - feeding a horse feed supplement containing magnesium can help to control this, but this should never be used in place of good grazing management.

Stress in the horse, caused by training, travelling and equestrian competition, can also cause a magnesium deficit and an excess of calcium - this can result in excitability, tension and muscle cramps.


The easiest form of magnesium as a supplement for horses to absorb is magnesium oxide, however other forms are available - including Magnesium Glutamate, Magnesium Aspartate, Calcium Magnesium (dolomite) often referred to as CalMag and magnesium sulphate more commonly known as Epsom salts.

Equine magnesium supplements come in several forms including powders and pastes in syringes for quick and easing dosing.

When feeding a supplement always carefully follow the manufacturers instructions to get the correct dose for your horse.

Claimed benefits of feeding magnesium supplements to horses

  • Calms nervous and excitable horses
  • Relaxes muscles.
  • Slows the heart rate
  • Slows down the absorption of sugars in the digestive system.
  • Can lessen the risk of Laminitis.
  • Helps to reduce equine obesity

Supplements containing Magnesium

  • NAF: Pink Powder
  • NAF: Relax
  • NAF: Thrive
  • NAF: Easy Going & Tempralax
  • Vita-Calm
  • LaminShield
  • Oxyshot
  • Nupafeed Liquid Horse Calmer


Magnesium is seldom overdosed but over supplementation can interfere with levels of potassium and sodium and although excess magnesium will be passed in the urine some major overdoses have been associated with renal and heart problems

Beware of Magnesium Sulphate , also known as Epsom Salts, which is a water hungry form of magnesium and will cause dehydration problems if fed for more than three consecutive days.

Epsom salts, although cheap, are also best known as a laxative.

Give too much and your horse or pony will experience diarrhoea.

A dose of Epsom Salts at anything more than one level tablespoon a day per 100kg of a horse's bodyweight is likely to cause diarrhoea.

Things to do before feeding Magnesium to your horse or pony

Consider why you want to feed an equine calming supplement to your horse.

If your horse or pony is excitable take time to analyse their feeding and work regimes. Too much high protein or carbohydrate feeds such as oats and/or not enough exercise can have disastrous consequences.

Too much new spring grass can also cause fizziness in a horse or pony - try restricting grazing if you think that it could be too rich.

A nervous horse may need a quieter environment - a busy stable yard with lots of noise can be unsettling for even the most docile of animals.

Schooling and patience may sometimes be the best long term answer to calming a "fizzy" horse.

Try riding out with an older, experienced calm companion to settle a hyperactive horse.

If you think that your horse is deficient in magnesium you can ask your vet to test a blood sample.

Tips on feeding Magnesium

  • Equine salt licks containing magnesium are available.

Other calming herbs, vitamins and minerals

  • Valerian
  • Taurine
  • Inositol - a B vitamin
  • Thiamin
  • L Tryptophane - an amino acid
  • St John's Wort (Hypericum)
  • Chamomile (contains magnesium)
  • Zinc

  Advice about the benefits of feeding magnesium supplements as an equine calmer
  to calm an excitable horse