A dog walker becomes obsessed with a client's dog after his personal trainer moves away. Tynan DeLong directs “Dog Runner,” a comedic character study about Brian, a keyed up Brooklyn resident who finds himself in a tailspin of anger and doubt. DeLong’s frequent collaborator, Brian Fiddyment, plays the man who can only think about fitness and Marti, a dog that isn’t his. He spends his days telling strangers about his love for dogs, and arguing with neighbors for being “piss shamed” (he lets Marti pee on Park Slope trees). When he finally gets his trainer on the phone, he struggles to communicate how deeply he’s flailing without him. After last year’s “Vonnie,” a heartfelt documentary portrait about his mother, DeLong returns to his baseline mode here — off-the-cuff comedy like he’s been pumping out effortlessly for the last couple of years (see “Dad & Step-Dad,” “Birthday,” and “Love is Stinks,” among others). He has a knack for one-liner loglines that allow for extreme and peculiar characters to behave childishly while injecting pathos with fears of being left out, left behind, or otherwise unwanted. -KA.

Directed by Tynan DeLong. Starring Brian Fiddyment. Written by Tynan DeLong and Brian Fiddyment. Featuring Louis Cinelli, Colin Burgess, Anthony Oberbeck. Produced by Sarah Wilson. Cinematography by Ryan Mooney. Edited by Tynan DeLong. Music by Tynan DeLong. Additional Music by Adam Schatz & Jason Nazary. Color Correction by Ryan Mooney. Camera Assistant: Caroline Yost and Alex Bliss. Production Sound by Matt Damiano. Production Assistant Michael Bernieri. Titles by Colin Burgess.