Donau's dam, Al Lone, was bred by H. B. Douglas and was foaled in Fayetteville, Tennessee in 1894. Al Lone was a semi-successful selling-plater with sixteen minor racing wins to her credit in 128 starts that was purchased by Thomas Piatt after her racing career ended in 1903. Al Lone produced Donau's full-brother, Wooltex, in 1909 at Brookdale Farm. Wooltex was later gelded and was a successful steeplechaser in the 1910s. Wooltex was bought by George S. Patton for $2,100 in 1912 and from Patton's personal correspondence, the gelding had a nervous and flighty personality similar to his older brother Donau.
