The Portuguese Warren Hound, otherwise known as the Portuguese Podengo, is a rare breed. Scarce in even their home country and threatened by extinction. This dog has a lively character, is intelligent and versatile. They can be used just as well for hunting, as a guard dog or simply as a pet.

Laddie Boy (July 26, 1920 – January 23, 1929) was an Airedale Terrier owned by U.S. President Warren G. Harding. He was born in Toledo, Ohio.

Benji is a rescue dog. He's referred to as a “mutt” in the movie, meaning he isn't one particular dog breed. He's a mix of multiple unknown breeds. He was labeled as a Border Terrier, but his trainers believed that he was a mix of Cocker Spaniel, Miniature Poodle, and Schnauzer.