| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Whadjathink | br. | c | 1988 | Seattle Song | Katerina the Great | Thoroughbred | USA | |
| Whakilyric | bay | f | 1984 | Miswaki | Lyrism | Thoroughbred | USA | |
| Whalebone | bay | c | 1807 | Waxy | Penelope | Thoroughbred | Great Britain | |
| Whartons Snail | c | 1710 | Thoroughbred | |||||
| What a Guest | chestnut | c | 1979 | Be My Guest | Princess Tiara | Thoroughbred | Ireland | |
| What a Pleasure | chestnut | c | 1965 | Bold Ruler | Grey Flight | Thoroughbred | USA | |
| What a Spot | bay | f | 2010 | Arch | Eversmile | Thoroughbred | USA | |
| What a Summer | grey | f | 1973 | What Luck | Summer Classic | Thoroughbred | USA | |
| What a Surprise | f | 1968 | Wise Margin | Militant Miss | Thoroughbred | USA | ||
| What A Treat | d.-bay | f | 1962 | Tudor Minstrel | Rare Treat | Thoroughbred | USA |