Horses lose key electrolytes and proteins through sweat at a much higher rate than humans, and if not adequately replenished, can significantly hamper performance and potentially cause dehydration.
Electrolytes are electrically charged minerals that keep many of the body's automatic processes balanced and running. While adequate water consumption is critical to staying hydrated, water alone does not replenish many of the key nutrients lost through sweat, like potassium, magnesium, and sodium. That's why seemingly every convenience store and sporting event is stocked with electrolyte-rich sports drinks.
But what about our horses? Well, they can't shop at the 7/11, and they don't need all that added sugar, anyway. But they certainly do need to maintain a healthy balance of electrolytes.
Be proactive. Replenish these key electrolytes and support healthy hydration with Electrolyte Pellets from Equithrive.
Do Not Stay Thirsty, My Friends 
Recommended for: horses of all ages and breeds during training, competition, travel, and periods of extended heat exposure. Simply add 3 scoops to the feed tub and always have fresh water available.
Ask the Vet: Is the Salt Block Enough?
Monty McInturff, DVM - Tennessee Equine Hospital
Salt contains electrolytes which helps cool the horse and improves the cardiovascular system. It also helps oxygenate the horse. The salt block really does matter, but it may not quite be enough.
When it's really really hot I encourage you to put an electrolyte supplement into the feed so that we know our horse is taking it in. Some horses are really great salt eaters and really great water drinkers, and some aren’t; so for [horses in heavy work] you should actually take an electrolyte pack and put a scoop into the feed. Be careful, some horses don’t take enough salt in. If you don’t take enough salt in, you tend to fatigue more quickly. Muscles need potassium, chloride, and sodium to help the cells recover while they’re working. It is very, very important.
Vern Dryden, DVM, CJF - Bur Oak Veterinary and Podiatry
Nutrition, for me, is a really important aspect of the equine athlete. I think that electrolytes are extremely important. Whether it's summer, winter, horses need to be hydrated to prevent colic, to prevent impactions, and maintain normal hydration status. One thing Equithrive has done is they have produced an electrolyte pellet that is palatable and really works. And I like the fact that there is no sugar added to these pellets, because a lot of the horses I treat are insulin resistant and many of the electrolytes that are out there have a lot of sugar in it to get the horse to eat it. This is a product that can suit any horse in any situation.