The show's writers had revealed one of the characters was to die, but fans have been stunned at the talking hound's demise.
Fans of the long-running TV show Family Guy have been left shocked after Brian, one of its main characters, was killed off.
The talking family pet, which met his end under the wheels of a car in an episode entitled Life Of Brian, has been replaced by a new dog voiced by Tony Sirico from The Sopranos.
However, viewers have taken to Twitter to express their outrage and anguish at his death, and have even launched a petition aimed at resurrecting the popular character.
Brian had been part of the animated show since it began back in 1999, and his demise came as a surprise to many given his key role in plot-lines and central relationship with precocious baby Stewie.
The production team had revealed they were going to kill off a member of the Griffin family, and replace them with a new character, but few expected it to be the articulate canine stalwart.
There was initially some doubt whether Brian's death was genuine, but the show confirmed his fatal departure with a tweet from its official account: "RIP Brian. #familyguy."
The dog, voiced by Family Guy creator Seth MacFarlane, bid farewell to the family in an emotional scene after being run over. Brian was quickly replaced by the new family dog, called Vinnie.
Steve Callaghan, the executive producer of Family Guy, said once the idea of killing off Brian had been suggested it "caught fire".
"We got very excited about the way this change will affect the family dynamics and the characters."
Family Guy is now in its 12th series, and has been nominated for 12 Emmy awards.