Concentration of sodium, chlorine, and potassium in the sweat of Colombian Creole Horses after performing a physical activity of moderate intensity and long duration was measured. Forty randomly selected horses were subjected to physical activity of moderate intensity, average 156 beats per minute (bpm) and long duration (40 minutes) under neutral environmental conditions. After exercise, sweat samples were collected from the upper third of the neck. Sample collection included cleaning of the area, delimiting the area with Vaseline and placing a protective gauze on the neck. The gauze was retired after exercise to proceed to apply filter paper for filter-lab® quantitative analysis on the sweat-soaked skin. The filter papers were transported to the laboratory in sterile glass jars. Concentration (m-equiv/L) of sodium, potassium and chlorine from sweat was measured with a digital vapor pressure osmometer. Data were analyzed using SPSS ® software. The average electrolytes values found had statistical normality and were similar to data reported in the literature for other horse breeds. The average sodium concentration was 252.25 ± 59.7 m-equiv/L, potassium concentration was 65.35 ± 18.5 m-equiv/L, and chlorine was 280.6 ± 70.2 m-equiv/L. We propose a water-electrolytic correction of sweat dehydration should be considered by administering oral beverages containing salts after a working session