Dornoch is out of Puca (Big Brown), winner of the Listed Steve Pini Memorial S. and placed at Grade 2 level, who has three stakes performers from three starters. Dornoch is a full-brother to the Grade 1 winner Mage, who won the 2023 Grade 1 Kentucky Derby and was second in the Grade 1 Haskell, and a half-brother to Puca's first foal Gunning (Gun Runner), a three-time winner who was twice stakes-placed. Puca is a half-sister to the Grade 1 winner and sire Finnegans Wake (Powerscourt).

Second dam Boat's Ghost (Silver Ghost) was a winner and stakes-placed. She is a half-sister to Ooey Gooey (Political Force), winner of the Listed John Wayne S., and to Father Wayne (E Dubai), who won seven races and was second in the Listed Gray's Lake S.

Third dam Rocktheboat (Summer Squall) won at two. Her close family includes the stakes winners Smooth Chiraz (Chitoz) and Okey Dokey Kyle (Tactical Cat).

Puca has a 2-year-old colt by McKinzie and foaled another full-brother to Mage and Dornoch on 4 April 2024.