Dall apparently suffered a spinal cord injury during a performance last week but information on how the injury happened was not available.

Poison has canceled their tour dates through September 2, a decision that eliminates the 22 remaining concerts on the Glam Slam Metal Jam outing that featured Poison, Warrant, Quiet Riot, and Enuff Z’Nuff.

“On behalf of Poison, I apologize to our fans and the promoters for having to cancel these dates,” lead singer Bret Michaels said in a news release. “Bobby Dall is my best friend and at this moment our only concern is for his well-being.”

Poison was to have performed at the South Dakota State Fair in Huron on August 5. Instead, Dall traveled a few hours away to the University of Nebraska Medical Center for surgery.

Dr. Robert Singer, who worked on several discs in the musician’s spine, said Dall will need at least six months of recovery.