Zooey Deschanel stars in the new Amazon Prime Christmas rom-com 'Merv' alongside Charlie Cox, portraying exes sharing custody of a depressed dog named Merv. Deschanel reveals that working with dogs on set is more challenging than expected, emphasizing that dogs are very serious and not there for snuggling during scenes. Gus, a rescue terrier mix, is the main canine star, trained to perform emotional scenes, and Deschanel praises his professionalism, noting he was perfect for the role. Director Jessica Swale highlighted the difficulty in filming emotional moments with dogs, explaining that only certain breeds and individual dogs can effectively convey the story on camera. Deschanel, who has three cats and is an animal lover, was drawn to the project because of its sweet premise, which explores the complexities of sharing custody of a pet after a breakup. The film features a holiday setting with humor, romance, and a possible reunion, making it a charming winter watch. Critics found 'Merv' to be heartwarming but somewhat lacking in chemistry and originality, with some noting that the film’s premise had been explored successfully in classic films like 'The Awful Truth.' The movie is now streaming on Prime Video.