Bicarbonate loading in the thoroughbred: dose, method of administration and acid-base changes.

This research explores the most effective dose, method, and timing for administering bicarbonate to thoroughbred horses. The studies determined that administering sodium bicarbonate through a nasogastric tube resulted in increased plasma pH levels after 8 hours. Attempts to feed it mixed with glucose were unsuccessful.

Objective and Methodology

• The research aimed to determine the optimal amount, method, and timing for ‘bicarbonate loading’ in Thoroughbred horses. This was examined via two different studies.
• In the first study, a solution of sodium bicarbonate or a water-based control solution was administered through a nasogastric tube to six horses. The blood acid-base status of these horses was then monitored for 24 hours following the procedure.
• The second study, administered a standard meal to four horses—both with and without bicarbonate supplementation—and subsequently tried adding glucose and sodium bicarbonate to the food.

Findings from Study 1

• The peak plasma pH was observed 8 hours after intubating sodium bicarbonate, with the levels remaining raised above that of the control group for 12 hours following the process.
• Although the blood PCO2 was generally seen to be higher than the control values after the administration of sodium bicarbonate, statistically significant differences were only recorded at the 4 and 5 hour marks following the procedure.
• The changes in plasma HCO3- and blood base-excess after administering sodium bicarbonate were found to be correspondingly similar, peaking between 3 and 6 hours after the procedure and remained higher than the control parameters 12 hours after the process.

Findings from Study 2

• The second study failed to alter the acid-base status of the horses by introducing sodium bicarbonate through the feed, as the horses did not entirely consume the feed mixed with sodium bicarbonate, despite efforts to improve the taste by adding glucose.

Conclusion and Suggestions

• The research suggests that future studies looking at the influence of sodium bicarbonate on exercise performance and metabolism should possibly involve administering it in a higher quantity than typically done (0.3 g/kg).
• For more accurate results, sodium bicarbonate should preferably be administered as a solution via a nasogastric tube at least 3 hours prior to exercise.