Both L- and D-lactate contribute to metabolic acidosis in diarrheic calves

Diarrhea in neonates is often complicated by metabolic acidosis. We used bl ood gas analysis and HPLC to determine whether bacterial fermentation might contribute to acidosis in diarrheic, calves. Diarrheic calves (n = 21) had significantly lower pH, PCO2 HCO3- and a higher anion gap than healthy cal ves (n = 21). Serum concentrations (mean +/- SD, mmol/L) of DL-, L- and D-l actate were also significantly higher in diarrheic (8.9 +/- 5.1, 4.1 +/- 3. 4 and 5.2 +/- 5.7) than in healthy calves (1.7 +/- 1.2, 2.0 +/- 1.1 and too low to quantify). D- and L-lactate accounted for 64% anion gap increase in diarrheic calves. Fecal D- and L-lactate concentrations were also signific antly higher in diarrheic calves (9.4 +/- 3.0 and 11.9 +/- 2.7 mmol/L) than healthy calves (1.1 +/- 0.1 and 1.6 +/- 0.1 mmol/L). The elevated concentr ations of serum and fecal D-lactate suggest gut bacterial fermentation cont ributes to the development of acidosis in diarrhea.