Just humor.

There is a fad of producing mixed breed dogs. We all heard about the 'labraddodle' (a mix of poodle and Labrador retriever) or the 'pickapoo' (a mix of Pekingeese and poodle). The story is going around that a Bull terrier male asked a shitzoo female if she would like to produce some offspring. "Naw," said the little female. "I am too small for you. Besides, do you want to breed puppies that would be called " bullsheetz?"