Changes in electrolytes, blood gas, osmolality, hematocrit, hemoglobin, base concentration, and anion gap in 11 detrained Arabian horses during exercise on a high-speed treadmill were investigated. After a period of three days of adaptation on the rolling mat, the animals were submitted to two exercises: one of short (maximum) and other of long duration (submaximum). Venous blood samples were obtained right before, and 30 minutes after the exercise. After the maximum exercise, it was observed a significative decrease in pHv, PvCO2, HCO3, and cBase and an increase in AG. It was also observed hypercalemia and increase in Ht and Hb. At the final of the submaximum exercise, it was observed significative increase in pH, cBase, SatvO2, and PvO2. So, maximum exercises can lead equines to present metabolic acidosis with respiratory alkalosis as response, hypercalemia and increase in hematocrit and hemoglobin, values. Submaximum exercises can present hypochloremic metabolic alkalosis but no alterations in the hydroelectrolitic balance.
equine; hemogasometry; eletrolyte; exercise