July/August 2025 Issue

EAST COAST EQUESTRIAN July/August 2025 Page 7 Hydration is the Key to Cool By Dr. Mike Lindinger & Gayle Ecker, Equine Guelph When horses work—especially in warm weather—their bodies heat up fast. If that heat isn’t released, their core temperature can rise to dangerous levels. Sweating is the horse’s main cooling mechanism, and while it’s effective, it comes at a cost: the loss of water and vital electrolytes like sodium, chloride, potassium, calcium, andmagnesium. Without replacing these, a horse’s performance, comfort, and health are at risk. This is just as true for horses standing in hot trailers for hours as it is for those competing in the ring or on the trail. Replacing What’s Lost For horses in light work, a bal- anced diet and access to loose salt usually provide enough support. But for those training several times a week or competing at high intensity, electrolyte loss can become a chronic issue. Sweat loss can exceed 10 to 15 liters per hour, and if not replenished properly, can lead to muscle fatigue, poor performance, or even serious heat stress. Practical Strategies to Support Hydration Here are key steps to help protect your horse from dehydration and electrolyte imbalance—whether you're preparing for a trail ride, hauling long distance, or competing in sport: Start With a Good Diet A quality diet lays the foun- dation for proper hydration. Add electrolytes to soaked feeds only if the horse has been sweating mod- erately or heavily. For lighter work, the natural salt and minerals in feed and hay are often enough. Always provide a clean salt block—but note that some horses won’t lick enough tomeet their needs.Youmay need to offer free-choice loose salt in a small wall-mounted container or mix it directly into grain during hotmonths. Pre-Event Electrolyte Support One to two hours before a long trailer trip or event, it may help to give your horse an oral electrolyte dose—but only if they are well-hy- drated. Electrolyteswork by drawing water into the gut, so if a horse is already dehydrated, this can backfire and worsen fluid loss. Make sure your horse drinks at least a gallon of water before or right after dosing. Soaking hay or feeding wet beet pulp four to five hours beforehand can also help by increasing gut water reserves. Choose the Right Supplements Electrolytes with glucose (dex- trose) can improve sodiumandwater absorption in the gut. However, too much sugar can lead to a blood sugar spike and insulin crash, potentially causing hypoglycemia during ex- ercise. Similarly, avoid fat-based supplements at rest stops, as they may slow electrolyte absorption. Fat has a place in the training diet, but not during competition breaks. Supplement Early —Don’t Wait Give electrolytes 1–2 hours before work and early during long rides or hot conditions. This can raise sodium levels and prompt your horse to start drinking sooner.Waiting until Quick Tip: Loose Salt Wins Many horses don’t con- sume enough from a salt block alone. Offer loose salt in a container or mix it into grain during hot spells. Don’t Dose a Dry Horse! Never give electrolytes to a dehydrated horse. It can worsen the problem by pulling water out of the bloodstream. Act Before You See Signs By the time your horse *looks* dehydrated, it’s already in trouble. Prevent the issue by supplementing early. First Water, Then Hay Feeding dry hay too soon after exercise can worsen dehydration. Let your horse rehydrate with electrolytes first. Hydration Rule of Thumb You can’t make up for poor preparation with last-minute electrolytes. Plan ahead, supplement smar t , and moni tor closely. (Continued on page 8)