First Down Dash, the most successful sire in Quarter Horse racing history, died on Thursday at Vessels Stallion Farm in Bonsall, Calif.\r\nThe cause of death was age-related, according to a statement released by the farm. First Down Dash was 26.\r\nThrough Friday, First Down Dash had sired the earners of a record $73.7 million, and 35 champions since his first crop reached the races in 1991.\r\nFirst Down Dash sired 1,163 winners and 224 stakes winners. He sired six winners of two of the sport&rsquo;s biggest races &ndash; the All American Futurity at Ruidoso Downs and Champions of Champions for older horses at Los Alamitos.\r\nBred in Texas by A.F. Stanley Jr. and B.F. Phillips Jr., First Down Dash won 13 of 15 starts and $857,256 in 1986 and 1987 for the Vessels family. First Down Dash was named the 1987 World Champion, and stood his entire stallion career at their farm in Bonsall, Calif.\r\nFirst Down Dash was by Dash For Cash out of First Prize Rose, by Gallant Jet. Dash For Cash was Quarter Horse racing&rsquo;s all-time leading stallion until surpassed by First Down Dash.\r\nThis year, First Down Dash is second on the progeny earnings list. Mr Jess Perry, the sire of All American Futurity winner Mr Piloto, leads this list with $4,097,516. First Down Dash has progeny earnings of $3,653,322. First Down Dash is the sire of three stallions among this year&rsquo;s 10 leaders by progeny earnings &ndash; Walk Thru Fire, Ocean Runaway and The Down Side &ndash; and the grandsire of another, Corona Cartel.