The responsible use of antibiotics helps keep animals healthy, which is better for the environment. When left untreated, sick animals grow more slowly, requiring more food and water. Thus, more grain must be grown for feed, which requires more fertilizer, water and farmland. So, sick animals have a larger environmental impact, while healthy animals use fewer natural resources. Practices that allow us to treat sick animals, resulting in the use of fewer natural resources, are good for the environment and good for everybody.