Objective: To determine and compare the effects of 4 oral replacement therapy (ORT) solutions on acid-base balance, abomasal emptying rate, and plasma volume expansion in calves with naturally acquired diarrhea and moderate dehydration.
Design: Prospective study.
Animals: 20 calves.
Procedures: 20 calves up to 45 days of age were randomly allocated (n = 5/group) to receive 2 L of 1 of 4 treatments via oroesophageal intubation: sodium bicarbonate (150 mmol/L or 300 mmol/L) or sodium acetate (150 mmol/L or 300 mmol/L). The 4 test solutions contained acetaminophen (50 mg/kg [22.7 mg/lb]) and 50 g of glucose monohydrate. Jugular venous blood samples were obtained periodically before and after administration of the ORT solution. Abomasal emptying rate was determined by use of the time to maximal plasma acetaminophen concentration.
Results: Plasma bicarbonate concentration increased more rapidly in calves administered bicarbonate-containing ORT solutions, whereas the rate of systemic alkalinization, as assessed via blood pH, did not differ consistently among treatments. The 300 mmol/L ORT solutions were emptied at a significantly slower rate from the abomasum than 150 mmol/L ORT solutions, with no difference in emptying rate between acetate and bicarbonate-containing ORT solutions of similar molality. The 300 mmol/L sodium acetate ORT solution significantly increased plasma volume.
Conclusions and clinical relevance: Clinically important differences in the resuscitative response to 300 mmol/L or 150 mmol/L ORT solutions of sodium acetate or sodium bicarbonate were not identified.