| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Achievement | br. | f | 1864 | Stockwell | Paradigm | Thoroughbred | Great Britain | |
| 1772-7 Achill | bay | c | 2012 | 643090000218033 | Flower Alley | Enterprise Beach | Thoroughbred | Lickity Split Services |
| Achillea | f | 1978 | Klondyke Bill | Reckless Lady | Thoroughbred | France | ||
| Achilles Way | chestnut | c | 2008 | Forest Wildcat | Unbridled Sea | Thoroughbred | USA | |
| Achin | bay | c | 2012 | 643094100237109 | 0625-4 Cherry Mix | 1601-4 Avva | Thoroughbred | Voskhod Stud |
| Aching Back | bay | f | 1944 | War Admiral | Drowsy | Thoroughbred | USA | |
| Achinsk | bay | c | 1971 | 3015 Gudzon | 3633 Azotnaya | Thoroughbred | Dnepropetrovsk Stud | |
| Achisai | chestnut | c | 1971 | 2416 Derzkij | 3212 Atletika | Thoroughbred | Voskhod Stud | |
| Acid Flight | chestnut | f | 1929 | Lemonora | Scutter | Thoroughbred | Great Britain | |
| Acidanthera | bay | f | 1995 | Alzao | Amaranthus | Thoroughbred | Great Britain |