Ridden by Hector Santiago for owner-trainer Jerry Delhomme, the gray filly was timed in :53.24 seconds for the 4 1/2 furlongs over a fast main track.
Bred in Louisiana by Spendthrift Farm, P Boo is out of the multiple stakes-placed Freud mare Paraiba. New York breeder Carolyn Vogel now owns Paraiba, having acquired the mare for $6,500 at the 2015 Fasig-Tipton New York Saratoga Fall mixed sale.
Dominus is a son of Smart Strike out of the multiple stakes-winning Lord At War mare Cuando. Campaigned by George Bolton, Stonestreet Stables, and Spendthrift Farm, he was a grade II winner on dirt and turf and retired to stud with earnings of $444,717.
The 8-year-old stallion stands at Spendthrift near Lexington for a 2016 fee of $3,500 and is part of the farm's "Breed Secure" incentive program, which delays payment of the stud fee until and only if the resulting foal is successfully sold at auction.