The 44-year-old star Zooey Deschanel has signed up to feature in the film that is being directed by Jessica Swale for Amazon MGM Studios.
The film centres on an estranged couple who find out that the dog they share is depressed following their break-up and decide to have an awkward reconciliation when they take their pooch on a sunny holiday to Florida to lift his spirits.
Linsey Stewart and Dane Clark have penned the screenplay with Matt Beer and Roma Downey producing the picture.
Zooey starred in the TV sitcom 'New Girl' as Jess Day between 2011 and 2018 but said last year that it was "too soon" for a reunion episode - even though she would love to spend more time with co-stars including Jake Johnson and Max Greenfield.
She told Us Weekly magazine: "No, it's too soon. We need a little more time in between. We always talked about '500 Days of Summer' [and] what's a different perspective on that.
"The things I'd like to revisit are my friends. I saw my castmates from 'New Girl' more than my family for seven years. I appreciate getting to work with them, so the thought of revisiting these things is mainly to do with the people."
Meanwhile, Zooey revealed how she thought it was a prank when she was told that the late music icon Prince wanted to appear on the show - with the pair duetting on the song 'Fallinlove2nite' for a 2014 episode.
She told The Guardian newspaper: "Oh my God. I don't know. I know he watched 'New Girl' on the tour bus.
"When he contacted me through his manager, I thought someone was pranking me and I asked my agents, 'Can you find out if this is really Prince's manager?'
"I recorded the song for the show, but when he said they would put it out I was like, 'What? A single with Prince?!' It was a pinch-myself moment."