VIEW ALL PHOTOS. U.S. Army's 1st ... which coincides with President Donald Trump's birthday. ... Alongside the herd of horses is their fiery two-year-old Blue Heeler mascot named Doc Holliday.

A Blue Heeler named Doc Holliday will join the Army’s 250th birthday celebration, a military parade in D.C. that coincides with Trump’s 79th birthday.

As the nation gets ready for a big military parade on June 14, held to commemorate the 250th anniversary of the U.S. Army, there is one unexpected guest star of the parade — a 2-year-old blue ...