Large-scale industrial farming of animals relies heavily on antibiotics. I’d go so far as to say that it wouldn’t be possible without the regular administration of antibiotics on relatively “healthy” animals. Otherwise, how else could they get away with crowding the animals into facilities that are sanitation nightmares? According to a new ad campaign launched by the Pew Charitable Trusts, up to 70% of antibiotics used in the U.S. go to farm animals that aren’t sick.