One Health acknowledges the links between human health, animal health and the environment. It seeks to improve and protect the health and well-being of all species by enhancing collaboration between veterinarians, medical and environmental professionals. Zoonotic diseases such as rabies and Salmonella infections are examples of how the health of people is related to the health of animals and the environment. Animals also share our susceptibility to some diseases and environmental hazards. Because of this, they can serve as early warning signs of potential human illness. For example, birds often die of West Nile virus before humans get sick with West Nile virus fever.
One Health approach is valuable for Public Health because it is primarily preventive and seeks to address public health threats at the source. One Health is not a new concept, and has become more recognized in recent years because of changes in the interactions among humans, animals, and the environment. One Health is actively supported by the Public Health Agency of Canada and the Centres for Disease Control and Prevention in numerous surveillance programs that monitor diseases spread between animals and humans.