After racing 722 m, 16 Greyhounds were evaluated to determine changes in hematologic, biochemical, blood-gas, and acid-base values following exercise. Values were determined before racing (T0), immediately after racing (T1), and 3 hours after racing (T2). Significant changes detected immediately after racing included increased heart rate, respiratory rate, and rectal temperature. Significant changes in hematologic values included increases in PCV, total plasma protein, hemoglobin, RBC, WBC, neutrophils, and lymphocytes. Change was not detected in values for monocytes, eosinophils, and neutrophil/lymphocyte ratio. Other increases included those for plasma concentrations of sodium, chloride, calcium, lactic acid, aspartate transaminase, alanine transaminase, alkaline phosphatase, creatine kinase, lactate dehydrogenase, and glucose. Concentrations of potassium and urea did not change. Measurement of blood-gas and acid-base status revealed significant increases in PaO2 and base deficit, whereas PaCO2, pH, and bicarbonate decreased. Three hours after exercise, all vital signs and blood-gas and acid-base values, except for PaCO2, which was still slightly low, had returned to baseline (T0) values. Most biochemical values had also returned to baseline, although sodium, chloride, aspartate transaminase, and creatine kinase were still high, and urea was low. Many hematologic values were still different from baseline values, with high values for WBC, neutrophils and neutrophil/lymphocyte ratio, and low values for PCV, total plasma protein, hemoglobin, RBC, and lymphocytes.