ELECTROLYTES

Electrolytes are minerals present in the horse in charged form (+ or -). The main electrolytes found in the blood are sodium and chloride, although calcium, potassium, magnesium, phosphorus, sulphates and bicarbonates are also present.

Potassium is the main cation (positively charged ion) in the cell as well as calcium, whose roles in the cell include regenerating energy, helping muscles contract and enabling the nerves to do their work.

Due to the differences in electrolyte concentrations in the blood and the cell wall, all the cells (and so the horse’s body as a whole) have a small electrical charge like microscopic batteries. Anything disrupting this balance will negatively impact the functioning of the cells and so the horse’s performance.

ELECTROLYTE REQUIREMENTS

The required electrolyte intake for horses that do not perform hard work corresponds to the maintenance requirement.

Most rations have a relatively low sodium content, so it is recommended to always have a block of salt on hand (salt consists of sodium and chloride).

The requirement changes when the horse starts to sweat due to work or warm weather, as large quantities of electrolytes are lost through the sweat. A small quantity , particularly magnesium and calcium, will also be lost through the urine in the event of intensive effort. More electrolytes will be lost through the urine in the event of muscle damage due to overwork.

COMPOSITION OF SWEAT

Not all sweat is the same. Human sweat is isotonic, which means it has the same electrolyte content as the blood. Horse sweat is hypertonic, which means that the electrolyte content is higher than the blood’s.

The main electrolytes lost through the sweat are sodium, potassium and chloride.

The duration and intensity of the effort also determine how much the horse sweats, together with temperature and air humidity. Obviously, there are differences between individuals. One horse will sweat more than another.

Sodium and chloride are the main electrolytes lost during endurance exercises and periods of warm weather; more potassium is lost during periods of warm weather.

Sodium loss requires the closest monitoring, as the body needs sodium to absorb and retain the water it requires to stop dehydrating.

Sweat also contains the trace elements iron, copper and zink. Trace elements are small quantities of a substance in the daily ration that should be sufficient to compensate any losses.

Electrolyte pre-loading is not really possible, but by giving the horse electrolytes before a competition you can at least be confidence that it will have sufficient quantities at the start. Electrolyte replenishment is clearly highly recommended after intense effort and heavy sweating.

It is very important that the horse has enough water to drink when it is given an electrolyte supplement; otherwise the electrolytes will draw water from the bloodstream and cause dehydration, which is clearly not the aim.

It is also very important that the horse is given sufficient roughage (at least 1% of the horse’s body weight), as horses that consume such volumes develop a larger reservoir of fluids and electrolytes in the colon, which can be used in the event of intense effort or warm weather (potential causes of dehydration).

A lack of thirst is a good indication that your horse is suffering from electrolyte deficiency, as sodium triggers a need for liquids in horses. Another sign is when you pull up the coat in the neck and it does not return to its original position immediately.

It is very important that your horse drinks sufficient water (at least 40 litres/day). Studies show that a horse’s speed and overall performance fall 5% when it is slightly dehydrated (2-3%).

Cavalor markets two electrolyte-rich products.

Cavalor Electrolyte Balance: electrolyte powder that can be added to the horse’s food or drinking water (25-50g/day)

Cavalor Energy Booster: electrolyte paste, which is enriched with amino acids and B vitamins to ensure fast recovery after competition

Peter Bollen
Equine Nutritionist