​Leonian's interest in motion photography found particular success in capturing horses. Several of his images were used by New York Racing Association to promote the Aqueduct Racetrack, appearing in print advertisements, subway posters, and race-day programs. He photographed a wide range of horse races and equestrian events, including the Belmont Stakes, harness racing at Roosevelt Raceway, horse shows at Fairfield, Ox Ridge, and Piping Rock, the Blind Brook Polo Club, and the 1968 Olympic pentathlon training. 

Pentathalon 1968 © Phillip Leonian

Big A © 1964 Phillip Leonian

Equestrian blue jacket © 1964 Phillip Leonian

Great Escape © 1964 Phillip Leonian

Harness Racer in a Red Blanket © 1966 Phillip Leonian

Trotter © 1966 Phillip Leonian

Trussed Up © 1966 Phillip Leonian

Beaupy Racing © 1964 Phillip Leonian

Rainy Day at Saratoga © 1964 Phillip Leonian

Cantering Thoroughbred © 1964 Phillip Leonian

Equestrian with Red Jacket © 1964 Phillip Leonian

Harness Racer Head On © 1966 Phillip Leonian

US Equestrian Team © 1968 Phillip Leonian

White horse equestrian © 1958 Phillip Leonian

Winners Spotlight © 1966 Phillip Leonian