He married Henrietta Margaret, from Scotland, and they had children John and James.
Traill owned a ranch in Argentina and imported polo ponies for the Roehampton Club, training them in Richmond Park.
He was also a coach at Ham Polo Club when it was revived by Billy Walsh.
His name appears as winner of the Roehampton Trophy several times, alongside teammates such as the Marquess of Villavieja, Jack Nelson and Major Philip Magor.
Traill won the Argentine Open ten times during his career.