When horses sweat it results in both loss of water and electrolytes. Electrolytes are charged particles, including sodium, potassium, chloride, calcium and magnesium. Loss of electrolytes causes fatigue, muscle weakness and decreases the thirst response from dehydration. Therefore, it is vital to replace both water and electrolytes in exercising horses. Horses should be supplemented with electrolytes the night before and the morning of heavy exercise to ensure adequate utilization. Avoid adding electrolytes directly to the water as some horses may not drink the water and therefore will become more dehydrated. Following exercise, electrolytes should not be given to a horse that is dehydrated; instead the horse must be re-hydrated before electrolytes are provided.
