May 6, 2026, 4:05 am | Read time: 3 minutes
Have you ever seen a horse sweat? When horses perspire, it can quickly look like they’ve been lathered. This is because when the animals produce sweat, a white foam forms. Horse enthusiasts know this from particularly warm days when it appears between the hind legs of their animals.
Why Do Horses Sweat Foam?
The noticeable foam that forms when horses sweat has a very specific cause. It’s due to a phenomenon that even some horse fans aren’t fully aware of. Responsible is a special protein in the animals’ sweat called Latherin. It acts like a mild foaming detergent and ensures that the sweat spreads better over the slightly oily, naturally water-repellent coat instead of simply beading off.
At the same time, this substance has soap-like properties. When movement and friction occur, the sweat begins to foam. That’s why the white foam primarily appears at typical friction points–such as between the hind legs, on the chest, or where the saddle and reins rest. This is exactly why a heavily sweating horse can quickly look as if it has been lathered.
Why Do Horses Sweat So Much?
Horses sweat not only quickly depending on movement but also quite a lot. Sweating is their most important and effective form of temperature regulation–especially during exertion, it reliably protects the body from overheating. This ability is also a crucial advantage in nature. As prey animals, horses rely on endurance and can remain capable over long periods thanks to their efficient cooling system.1
Because the animals’ coat is slightly oily, the sweat must cover the body extensively to unfold its cooling effect. This way, heat is effectively released through evaporation. From certain angles, this process can even be observed: The horse seems to steam as the moisture rises from the warm body.
Why Cats Can Drink Saltwater
Can Dogs Eat Pretzel Sticks?
How Many Liters Does a Horse Sweat?
How much a horse sweats depends heavily on temperature, exertion, and training condition–but the amounts can be impressive. Even with light work, a horse loses several liters of sweat, while with intense exertion, it can quickly be between seven and twelve liters.
In extreme cases, such as high heat or strenuous training, even up to 15 liters or more are possible. It’s not just about water: With sweat, the horse also loses important electrolytes like sodium, chloride, and potassium, which must be replenished afterward.
How much a horse has sweated can often be seen well on the coat–from slightly damp spots to dripping wet skin and visible foam formation at typical friction points.2
What Should Owners Do When a Horse Sweats a Lot?
If a horse sweats heavily, it loses not only water but also important electrolytes like sodium and chloride. These are indispensable for muscles and nerves. A deficiency can quickly lead to a drop in performance or exhaustion.
Therefore, fresh water must always be available, and a salt lick is part of the basic equipment. For horses that regularly sweat heavily, additional salt in the feed can be useful to compensate for the losses. Horses usually get enough potassium from hay or grass.
Additionally, owners should adjust training during heat, avoid intense sessions, and ensure sufficient shade. If fluid and electrolyte loss is not compensated, dehydration and overheating can occur.
However, if a horse becomes unusually foamy or sweats without apparent exertion, it can also indicate stress or overexertion.