After beating the competition at the nationals, the Jack family prepares for the International World of Wiener Dog Racing. Without parental consent, the kids must sneak off to the races, otherwise their notorious, beloved underdog, Shelly, will have to forfeit her U.S. title at the competition. But the stiff competition leads several of the other countries to get involved in foul play that only the real winners can sniff out!

When Melanie and Phil ask their son Danny what he wants for his birthday, they are greeted with the response that every parent dreads: a dog. When Danny selects his dog from the local shelter he lovingly names her Shelly in honour of all sheltered dogs. Realising that Shelly has a talent, Danny decides to enter her in the illustrious Wiener Dog Nationals race. Only one thing stands in their way: Ms Merryweather and her champion dog Princess.

Wiener-Dog tells several stories featuring people who find their life inspired or changed by one particular dachshund, who seems to be spreading a certain kind of comfort and joy. Man’s best friend starts out teaching a young boy some contorted life lessons before being taken in by a compassionate vet tech named Dawn Wiener. Dawn reunites with someone from her past and sets off on a road trip picking up some depressed mariachis along the way. Wiener-Dog then encounters a floundering film professor, as well as an embittered elderly woman and her needy granddaughter—all longing for something more.