Equine america apple lytes as horses work and sweat they lose vital electrolytes and mineral salts at low levels these can be replaced with sodium chloride salt but if the horse is in medium to hard work and sweating on a daily basis an electrolyte supplement must be provided without electrolytes the horse will feel lethargic and a continuation of this loss is highly detrimental to the horses health as the main electrolyte is a salt sodium chloride it is important to use a sa