Sodium bicarbonate is used as an antacid, a cleanser, and to replenish electrolytes. For years, it has been common practice to administer small quantities of sodium bicarbonate or other alkalinizing agents prior to a race.
Theory suggests that a small amount of sodium bicarbonate will help the horse recover after a race by dissipating muscle lactate. It is also used to prevent "acidosis," related to high grain intake. So far, there is no scientific basis to support these supposedly beneficial effects.
Sodium bicarbonate is also used to treat metabolic acidosis associated with colic in horses.