Experimentally induced hyperchloremic and dl-lactic acidosis in calves: An attempt to study the effects of oral rehydration on acid-base status

Abstract

Many diarrheic calves suffer from metabolic acidosis, which is commonly treated by oral rehydration therapy. Oral rehydration solutions can be prepared in water, milk, or milk replacer. Therefore, the aim of the study was to verify dietary effects of water- or milk replacer-based oral rehydration solutions on parameters of acid-base balance in calves with experimentally induced hyperchloremic and dl-lactate acidosis. In 12 calves, hyperchloremic or dl-lactate acidosis was induced by HCl or dl-lactic acid infusions according to protocols outlined in previous literature. Immediately after induction, the calves were fed with milk replacer or water- or milk replacer-based oral rehydration solutions, or remained fasting, respectively. Blood samples were taken to monitor acid-base status over an experimental period of 4h. Using the protocols, all calves revealed a manifest hyperchloremic or dl-lactate acidosis. Because of high infusion volumes, plasma volume was expanded and effects of feeding regimens on blood parameters were rare. Unexpected clinical aberrations occurred after repeated induction of dl-lactate acidosis: all calves developed a thrombophlebitis of the jugular vein, whereas HCl infusion had no effect on endothelium. Induction of acidosis via infusion is not suitable to study dietary effects. A protocol to induce acidosis and dehydration simultaneously is required to duplicate the metabolic conditions of diarrheic calves. In further investigations, attention should be focused on effects of d-lactate or its metabolites on endothelial tissue.

Intravenous administration of a polyionic solution containing 84 mEq/l of lactate resolves experimentally induced hyperchloraemic acidosis in horses

“…The mild somnolence observed during the infusion of HCl solution ceased soon after the end of the infusion, even with the maximum degree of acidaemia at that moment (7.12 ± 0.05 and 7.09 ± 0.03 in control and treatment groups, respectively). This is in agreement with what has been observed in calves . Moreover, all horses in this study underwent induction of hyperchloraemic acidosis twice, with consistent findings.…”

“…Severe hyperchloraemic metabolic acidosis was induced in healthy horses with the infusion of 100 mmol/l HCl solution at 10% of body weight and the induced imbalance was similar in degree to that demonstrated in newborn calves given intravenous infusion of HCl solution , despite differences in the volume, the concentration of HCl, and the infusion rate of the solution used here. A previous study in healthy ponies showed a mild acidosis probably due to a lower volume of the HCl solution infused (2.5% of body weight) .…”

Experimental protocol for metabolic acidosis induction by intravenous administration of hydrochloric acid in sheep

“…The experimental protocol for the induction of metabolic acidosis used in the study was efficient for inducing severe hyperchloremic metabolic acidosis at the end of the infusion. Experimental protocols for hyperchloremic metabolic acidosis induction by intravenous HCl solution have been studied in ponies (Gossett et al, 1990), horses (Romão et al, 2017), and newborn calves (Abeysekara et al, 2007;Gentile et al, 2008;Schwedhelm et al, 2013). These protocols have been effective in inducing metabolic acidosis; however, the severity of the imbalance, the infused volume and the rate of administration varied between the studies.…”

“…Although the infusion rate and volume were similar to those used in this study, the solution infused by these authors was three times more concentrated, which resulted in a more severe imbalance. Gentile et al (2008) and Schwedhelm et al (2013) infused calves with a solution containing the identical concentration used in this study. A volume equivalent to 10% of the calf's BW was infused in only 80 minutes, which caused severe metabolic acidosis at the end of the infusion.…”

“…models reproducing hyperchloremic acidosis have been studied in ponies (Gossett et al, 1990), horses (Romão et al, 2017), and calves (Abeysekara et al, 2007;Gentile et al, 2008;Schwedhelm et al, 2013) and consisted of the intravenous administration of hydrochloric acid (HCl) to induce metabolic acidosis. These authors used different protocols for induction; thus, different results were observed, particularly regarding the severity of the imbalance.…”