This chapter envisages a world in which antimicrobials and other medicines in our current armoury against diseases have been replaced by a caring for animals that are healthy because they are happy. Good welfare and happy animals are prerequisites for effective immunity. A greater awareness of improved environments for animals and optimum population sizes (including that of humans) will enable better living conditions to be implemented for the benefit of animal health. While we recognise that a healthy diet, healthy environment, and healthy genetics are needed for intensive animal production, we continue to raise animals in unhealthy conditions. As well as keeping unhealthy animals in farms, laboratories, zoos, and our homes, the risk to the health of wildlife and humans from the spread of diseases is dire.