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

Area of Science:

• Equine Sports Medicine
• Animal Physiology
• Nutritional Biochemistry

Background:

• Bicarbonate loading is a strategy to enhance athletic performance by buffering lactic acid.
• Optimal methods for administering sodium bicarbonate (NaHCO3) in Thoroughbred horses are not well-established.
• Previous attempts at oral supplementation have faced challenges with palatability and consumption.

Purpose of the Study:

• To investigate the optimal dose, route, and time course for bicarbonate loading in Thoroughbred horses.
• To evaluate the effectiveness of nasogastric intubation versus oral administration of NaHCO3.
• To determine the impact of NaHCO3 administration on blood acid-base status.

Main Methods:

• Study 1: Six horses received NaHCO3 or water via nasogastric tube, with blood acid-base status monitored for 24 hours.
• Study 2: Four horses were fed a standardized diet with or without NaHCO3 supplementation, followed by a trial with added glucose and NaHCO3.
• Blood pH, PCO2, HCO3-, and base-excess were measured.

Main Results:

• Nasogastric administration of NaHCO3 significantly elevated plasma pH, HCO3-, and base-excess for up to 12 hours post-administration.
• Peak effects on acid-base status occurred between 3-8 hours after nasogastric intubation.
• Oral administration of NaHCO3 mixed with feed, even with glucose, was unsuccessful due to incomplete feed consumption.

Conclusions:

• Nasogastric intubation is a more effective route for bicarbonate loading in horses compared to oral administration with feed.
• Future research should consider higher doses and nasogastric administration at least 3 hours prior to exercise for optimal results.
• The findings provide guidance for optimizing sodium bicarbonate supplementation strategies in equine athletes.