Yes, pet shops are infamous for doing such things as telling prospective buyers that they are purebred, going as far as changing the breed name so VERY slightly on "papers", that it sounds like a new breed of dog, when it's only a mix.

They are also guilty of buying dogs and cats from puppy and kitten mills. I stay out of pet stores because I get so angry when I see those puppys and kittens, who are so OBVIOUSLY sick that I go off on them, sometimes creating a scene. What really bugs me the most is the they have the GALL to charge such outrageous prices for a simple kitten or puppy that could easily be adopted from a shelter.