Seth MacFarlane, the creator of the hit animated shows “American Dad” and “Family Guy,” has suspended production on his TV series. He and his showrunners are seeking a new contract with the Writers Guild of America.

MacFarlane, a longtime advocate for the WGA who participated in the last strike in 2007-2008, “American Dad’s” Brian Boyle and Matt Weitzman and “Family Guy’s” Rich Appel and Alec Sulkin are signaling their dissatisfaction with 20th Television and have joined

the writers on strike and won’t resume production until an agreement is reached with the WGA, Deadline reported.

“Family Guy” already completed its 21st season on May 7, with a total of 20 episodes. “American Dad,” which has about 3 months of scripts, voice recordings, etc. completed, and the animated show already began its 20th season in late March, has time before 20th Television has to worry about not having enough new episodes.

“Family Guy” has been renewed for two more seasons, 22nd and 23rd, while “American Dad” has been renewed for its 20th and 21st seasons. Recently, showrunners Boyle, Weitzman, Appel and Sulkin were notified to report for their “non-WGA duties”. However, the definition of these duties has caused tension between the WGA and the studios, as the guild believes that being a showrunner only includes writing duties.

MacFarlane’s “Family Guy,” nominated for 12 Primetime Emmy Awards and winning three, and “American Dad,” four Primetime Emmy Awards, are acclaimed hits on FOX and in syndication.

MacFarlane is fighting on behalf of the WGA union, which represents 11,500 writers, against the Alliance of Motion Picture and Television Producers (AMPTP), a trade association representing more than 350 American television and film production companies, including Paramount Pictures, Sony Pictures, Universal Pictures, Walt Disney Studios and Warner Bros.

According to sources, while many prominent showrunners and talent have received suspension letters from NBCUniversal, Seth MacFarlane and his production company, Fuzzy Door Productions, who left a deal with 20th Century Fox Television last year for a $200 million deal with NBCUniversal, have not received such a letter.