Sodium (Na)


Fifty % of the body’s sodium is found in bones. The other part is used to regulate the hydro-electrical and acid-base balances within the body. It is mainly extra-cellular. The main losses occur through milk, urine and sweat. Sodium is also stored in the large intestine.

Electrolytes and their roles:

  • Stimulation of thirst (rehydration/renal function)
  • Regulation of nerve impulses (balance of electrical charges)
  • Regulation of muscular contraction/relaxation cycles (lack of electrolytes =>myopathy)
  • Involvement in blood coagulation

Pay attention, a single excessive dose may induce stomach ulcers.

A lack of muscle relaxation can be induced by a hydro-electrical unbalance.

Sodium (Na)

Electrolytes and rehydration:

Electrolytes loss in sweat in the healthy adult horse is essentially linked to the work load, temperature and humidity.

In extreme conditions a horse may lose up to 12 litres of sweat per hour. (Weigh your horse before and after effort!)

Sweat composition:

  • Sodium (3.1 g/l)
  • Chloride (5.3 g/l)
  • Potassium (1.6 g/l)
  • plus calcium, magnesium, phosphate,…

Feed can compensate for some electrolytes losses:

  • Forage is rich in electrolytes
  • A salt block furnishes an average of 10 g of salt per day (just enough to cover the  needs for a horse at rest)
  • Additional electrolytes must be given after heavy exercise or in hot conditions.

For a good use of electrolytes in horses

Regulation of nerve impulse (balance of electrical charges):

The risk of accident is increased if the horse is dehydrated, because of a lack of water but also of electrolytes.