The exceptionally mild Megan Leavey should come with a “must love dogs” disclaimer

It’s undeniably heart-melting to see an animal demonstrate a pure and abiding devotion to its human companion. That is the operating premise of just about every animal-related drama that doesn’t end in a tragic mauling. The key to turning that premise into a workable film are the specifics of the human. Otherwise, why not just watch YouTube videos of dogs welcoming their soldier owners home from active duty? As it happens, Megan Leavey seems well-positioned to offer a variation on both general dog-and-human friendship and specific dog-and-military-human loyalty. Based on a true story, because there may not be any point in fully inventing a story about a dog and a human liking each other, the movie follows Megan (Kate Mara) as she flees her dead-end life in semi-upstate New York by enlisting in the Marines. She finds her calling when she becomes the handler for an aggressive but well-trained bomb-sniffing dog.

Immediate narration from Megan explains how she has to leave her old life behind, because she’s completely checked out of it—conditions, in other words, that are perhaps better communicated visually rather than verbally. She’s adrift in part because her childhood best friend has died, which she also explains in voice-over, even though this information seems designed to be revealed later in the movie when she gives more details to her friend and possible love interest, Matt (Ramón Rodríguez). This experience, along with her insensitive mother (Edie Falco), has left Megan alienated from people, but her pre-military life breezes by so quickly that her supposed unpleasantness doesn’t really register, much less snap.

This wouldn’t be a problem if Mara was supposed to be playing an empty shell. Instead, the movie insists that she’s an active fuckup with one last chance to prove herself, a position seemingly supported by a single incident of drunken partying with characters not seen before or after this one scene where they get excited about Lit’s “My Own Worst Enemy” blasting in a bar (admittedly, a nice early-’00s period detail). This happens after Megan has successfully made it through boot camp, diminishing the sense of desperation on her part.

But Megan does focus up further when, assigned to cleanup duty at the K-9 training facility, she glimpses the close bond between military dogs and their handlers. She pursues a position there and eventually gets assigned to Rex, the most temperamental of the dogs. They train together and are deployed to Iraq to sniff out improvised explosive devices. This progression from Marine to dog-handling training to Iraq is interesting as a procedural. But apart from a couple of decent suspense sequences, shot with the same handheld camerawork always used for depicting Iraq (albeit with the addition of some neat ground-level shots to get on Rex’s wavelength), the narrative remains relatively slack. Megan Leavey keeps leaping forward—mostly a month at a time, but at one point much longer—without any weight behind it. There’s little discernible difference between cuts to the next morning and cuts to the next year.

This leaves the movie to get by on the easy stuff: nice humans and nice dogs all liking each other. The bond between Megan and Rex is sweet, as is the developing romance between Megan and Matt; Rodríguez and Mara have pleasant chemistry, as far as it goes. But the rough stuff—of training, of combat, even of dialogue between soldiers—is sometimes weirdly sanitized, as if hedging for any kids who might be in the audience. Director Gabriela Cowperthwaite, making her fiction feature debut following her animal-centric documentary Blackfish, doesn’t get to the core of Megan’s loneliness until the last half-hour or so, when she returns Stateside. Even then, a crusade on Rex’s behalf feels a little perfunctory. When Megan Leavey touches upon the treatment of post-traumatic stress disorder in both humans and animals, it looks capable of bringing something novel to the human-and-dog formula. Most of the time, it’s a rote biography of someone a dog really liked.