Whitfield has introduced, sponsored and helped pass several bills to strengthen and insure the humane treatment of animals in the United States. He is a recognized leader regarding the humane treatment of animals. His major national accomplishment may have been the banning of U.S. horse slaughter for human consumption, with an amendment that barred the U.S. Department of Agriculture from spending money on inspections of horse slaughterhouses, which fed demand for horsemeat in some European and Asian countries. The ban is no longer in place, but it had the effect of killing the horse-slaughter industry in the U.S.