Acey-deucy
Uneven stirrups, popularized by Hall of Fame jockey Eddie Arcaro, who rode with his left (inside) iron lower than his right to achieve better balance on turns.

Across the Board
A bet on a horse to win, place and show. If the horse wins, the player collects three ways; if second, two ways; and if third, one way, losing the win and place bets. Actually three wagers.

Action
1) A horse's manner of moving. 2) A term meaning wagering -- The horse took a lot of action.

Acupressure
Utilizing stimulation on acupuncture points to treat an animal.

Acupuncture
A centuries-old means of treating an animal or human through the use of needles, electrical current or moxibustion (heat and herbs) to stimulate or realign the body's electrical fields.

Added Money
Money added to the purse of a race by the racing association or a breeding or other fund to the amount paid by owners in nomination, eligibility, entry and starting fees.

Added Weight
A horse carrying more weight than the conditions of the race require, usually because the jockey exceeds the stated limit.  

Adequan
Brand name for polysulfated glycosaminoglycan, used in the treatment of certain arthritic conditions.  

Age
All Thoroughbreds celebrate their birthday on Jan. 1 

Agent
A person empowered to transact business for a stable owner or jockey, or empowered to sell or buy horses for an owner or breeder.