Is there a formula or recipe for making an electrolyte supplement to be given to horses during or after events in hot weather?

Many people think their horse needs electrolytes during the summer. Provided the horse is conditioned properly and is consuming a properly balanced diet, supplemental electrolytes probably are not necessary. However, during extremes of temperature and humidity, the horse may need an electrolyte solution, but it should not be needed or given on a daily basis. If you think a solution is needed, make sure the horse has a choice between the solution and plain water.
A horse that is working …