The answer (if you eat meat) is that, chances are, you probably already do.
However, dried poultry waste and sewage sludge are routinely fed to cattle. Pigs and chickens are still routinely fed the bones, brains, meat scraps, feathers, and feces of their own species. Furthermore, tens of millions of shelter animals are also picked up by rendering plants. Thus commercial meat, dairy, and egg products often come from animals whose diet included the ground up remains of cats and dogs, including the euthanasia drugs injected into their bodies. 40 billion pounds a year of slaughterhouse wastes (blood, bone, viscera) and euthanized cats and dogs from veterinarians and animal shelters, are rendered annually into livestock feed. Moreover, the Food and Drug Administration has been using inaccurate, incomplete, and unreliable data to track and oversee feed ban compliance.”