While attending Joliet Junior College in 1969, Pinnick was inspired by hard rock bands such as Led Zeppelin and Jimi Hendrix.

After attending college for roughly six months, Pinnick dropped out and joined a traveling gospel band called The Spurrlows.

In the mid 1970s, Pinnick formed a band called Servant, with keyboardist Matt Spransy, that played progressive art rock along the lines of Yes and Emerson, Lake & Palmer.

Spransy joined the other band in the late seventies and recorded "I'm Gonna Live" for the 1981 album Rockin' Revival that he and Pinnick had written together.

In 1979, Pinnick was invited to join a band that was forming in Springfield, Missouri with singer Greg X. Volz of Petra fame.

He was soon offered a spot in guitarist Phil Keaggy's touring band, along with the drummer from the failed Volz project, Jerry Gaskill.

He is highly sought-after by other artists for album guest appearances, as well as membership in several side bands and recording projects.

[5][6][7] Diamante Music Group canceled distribution of King's X material in Christian retail stores following this information becoming public knowledge.

[13] In March 2018, it was announced that original member of the proto punk band MC5, Wayne Kramer, would embark on a 35-date tour of North America for their 50th anniversary of the band's debut, Kick Out the Jams, recruiting Pinnick to play bass along with Kim Thayil of Soundgarden, Brendan Canty of Fugazi, and Marcus Durant of Zen Guerrilla.

Doug dropped the Poundhound moniker for his third solo album, Emotional Animal, instead crediting himself as "dUg Pinnick."

He sang lead vocals on the eponymous debut album by former Winger guitarist Reb Beach's band The Mob, released in 2005.

He performed guest vocals on the Black Sugar Transmission track "Runnin' Like a Dog", which was released on the band's e.p.

He also performs with King's X partner Ty Tabor, along with former Galactic Cowboys members Wally Farkas and Alan Doss, as a group called The Jibbs.

Hal Sparks used several tracks off of Pinnick's Strum Sum Up CD as his musical accompaniment during his magic show performances on VH1's Celebracadabra that aired in 2008.

Pinnick's side project, Tres Mts., with Jeff Ament of Pearl Jam and Richard Stuverud of the Fastbacks, released their album, Three Mountains, through Monkeywrench Records in March 2011.

In March 2014, Pinnick's all-star side project KXM, featuring former Dokken guitarist George Lynch and Korn drummer Ray Luzier, released their eponymous debut album through Rat Pak Records.