Blood buffering in sedentary miniature horses after administration of sodium bicarbonate in single doses of varying amounts

SUMMARY Blood acid-base and electrolyte status was studied in four sedentary Miniature Horses treated with 200, 300, 400 and 500 mg of sodium bicarbonate (NaHCO 3 ) per kg of body weight (BW). Arterial blood was collected before treatment with NaHC0 3 and each hour for 5 h after treatment. All treatments resulted in an increase in blood pH, bicarbonate (HCO 3 − ) concentration and base excess (BE) by 1 h post-dosage, which continued through the 5th hour (P 3 /kg BW resulted in less elevated blood HCO 3 − concentrations (P 3 , plasma Na + concentrations increased among all treatments but declined to initial values by 3 h post-treatment. The 200 mg NaHCO 3 /kg BW dosage resulted in the smallest increases in plasma Na + concentrations (P + and Ca ++ concentrations were lower (P .05) among treatments. All NaHCO 3 dosages increased blood buffering capacity as indicated by increased blood pH, HCO 3 − concentration and BE. Maximum blood pH, HCO − 3 concentration and BE was reached using a dosage of 300 mg NaHCO 3 /kg BW. Also, all treatments altered the plasma electrolyte concentrations.