Death of Jim Parsons' dog helped him make decision to quit The Big Bang Theory

Jim Parsons has recalled that the death of his dog was a big factor in why he walked away from The Big Bang Theory after 12 seasons.

Jim's decision to leave the long-running comedy series prompted producers to call it quits on the show, which ended last year.

Appearing on the latest episode of David Tennant's podcast series, Parsons admitted he knew he was signing his last The Big Bang Theory contract when he agreed to extend his role as boffin Dr. Sheldon Cooper for two final seasons.

"Our final contract was for the last two years, but no one knew when we signed it what that would mean," he said.

Recalling: "I kind of had a suspicion in my heart that that was going to be it for me when I did sign that contract," Jim reflected: "I was exhausted (and) I was really upset about, more than anything, one of our dogs was getting really at the end of his life around then (sic)."

Days later Jim had to put his pet down and then he broke his foot.

"The bottom line was that it was a really intense summer," he explained, "The dog passing away, he was 14, and (boyfriend) Todd and I had been together for 15 years at that point, so it just was the end of an era."

Earlier this year a producer on The Big Bang Theory revealed there were plans to extend the show for another two years before Parsons quit.

"Jim Parsons... said he couldn’t come back and do anymore," production designer John Shaffner said, "And (creator) Chuck (Lorre) had always said if one member of the cast left the show then the show would have to end."