In this article, we present 2 case reports of puppies less than 4 mo of age at the time of infection with the nematode known as giant red kidney worm (Diotophyma renale). The first puppy was prepared for an ovariohysterectomy that evolved into an exploratory laparotomy. An inflamed omentum was observed, and D. renale infection was suspected due to the puppies' place of origin. The algorithm developed by the Ontario Society for the Prevention of Cruelty to Animals for the diagnosis and treatment of D. renale infections in dogs was followed. Both puppies had a history of origin from northern Manitoba, Canada. Due to the puppies' ages, the authors suspect that the transmission of infection for both puppies could be transmammary, transplacental, or ingestion of paratenic hosts or that these cases challenge what is thought to be the current prepatent period. In addition, D. renale infections in dogs, especially from northern communities, could be common.