Around the Water Trough

Basics of Sweating and Electrolytes

Shannon Habenicht

By Emma Ford | World Class Grooming

Why do horses sweat?

Horses sweat as a means to cool down and reduce their internal temperature. Sweating can be caused by high temperatures, exercise or from pain. (For the purpose of this article, sweating from exercise will be the main focus.) During exercise the muscles will produce heat which the horse tries to regulate through his breathing and skin. The blood carries the heat to the lungs to dissipate and then to the skin where it can radiate from the body. If the amount of heat buildup is more than can be regulated this way, then the horse’s internal organs start to heat up. At this stage the horse starts to sweat to aid by evaporation and the cool down process.  

Sweat mainly contains water plus minerals, the major ones being sodium, chloride potassium, calcium and magnesium, also known as electrolytes. These are required in part to regulate muscle function, if there is an imbalance of these minerals then muscle fatigue will occur. How much your horse sweats depends on ambient temperature, level/type of exercise and fitness level of you horses. In prolonged exercise periods, especially if hot weather, horses can lose up to 10 to 15 liters of fluid in an hour. These fluids need to be replaced for your horse to feel relaxed and fit the next day.   

Emma and Z cooling out Kentucky Three Day Event 2018 | PC: JJ Sillman

Emma and Z cooling out Kentucky Three Day Event 2018 | PC: JJ Sillman

One sign to be aware of if your horse is struggling to regulate his temperature can include heavy breathing or panting, this is a sign your horse is trying to cool down by faster breathing, very often this can lead to “heat stroke” if not corrected quickly. The internal temperature can rise to a dangerous high between 106* and 110*, if left for too long, internal organs can be damaged along with disruption to the digestive tract. Knowing how hot your horse is after exercise and how fast he typically cools out under “regular” weather/type of exercise conditions is important to determine. A horse fit enough for what is being asked of him should be able to drop his temperature by 1 - 2 degrees and breathing rate by approximately 20 beats within the first 10 - 15 minutes of cooling down.  

Fernhill Cubalawn giving us his opinion of a hose off!!

Fernhill Cubalawn giving us his opinion of a hose off!!

A horse over sweating and panting is an easy candidate for being dehydrated. Under these circumstances cooling out with cold water is very beneficial to decrease temperature by evaporation. Finding shade and a breeze, maybe fans, can be very beneficial to cool horses down faster, especially if it’s humid. Allowing your horse to drink water is a must. There are different schools of thought of whether you should allow small quantities at a time or let the horse drink what he wants. Allowing him to drink a gallon of water at a time is going to do more good than harm. In cooler climates, but when your horse has worked hard, offering tepid warm water will sometimes encourage your horse to drink more than cold water.

Should your horses continue to show signs of heavy panting and increased temperature after half an hour of cooling then a vet should be consulted as soon as possible.

Should you add electrolytes you might ask. Not all horses need supplemental electrolytes. If clean fresh water, quality forage and a good fortified feed is being utilized then most horses do not need a supplemented source of electrolytes. They expel the minerals they don’t need so feeding extra does not make sense. How much your horse sweats during exercise is the best gauge of whether electrolytes are needed. If your horse sweats, then replenishing with just water isn’t enough. That would only dilute the remaining minerals available for the required body functions. Should your horse feel muscle stiff and sore the day after a hard workout, the likelihood is that his electrolyte balance was incorrect. Using the skin pinch test can be an indication of dehydration, if a small section of skin is held and then released it should spring back into place. Remaining tented can be a sign of dehydration. 


Quality named brand electrolytes are abundant in stores or you can use table salt mixed with lite salt at a 3:1 ratio. If you choose a paste rather than powder, giving a small quantity of hay/feed prior can reduce irritation of the stomach.

If your horse is a non-sweater, also known as anhidrosis, this can be a huge problem as he will have a very hard time regulating his temperature. You should consult your vet if you think this could be an issue. Practical advice for this issue includes riding in the cooler parts of the day, making sure your horse has adequate shade and ventilation in his paddock and stall, plan your fitness schedule around the weather, and don’t gallop on extremely humid days. Cooler climates can help to ‘reset’ the body and initiate sweating again. 

Tips for encouraging drinking on long hauls.

horse quencher.jpg

Horses often lose fluid whilst traveling, they may not sweat but the stress of travel can be hard on their bodies. Hydration is key for a fit arrival. Taking your own water from your barn can sometimes help with picky horses and adding carrots and apples is a good “go to”. Adding a handful of sweet feed or using a known product such as Thirst Quencher can be helpful for some horses to get their noses in the water bucket. Soaking a hay net for at least 10 minutes can add water intake, as well as feeding small “sloppy” mashes during long haul if needed. 

Hope you enjoy a HYDRATED rest of your summer!