One Health is the concept that the health and well-being of people is linked to the health of their animals and the environment. It is nowhere more true than in the Horn of Africa (Kenya, Ethiopia, Eritrea, Somalia, and Djibouti) where many people’s livelihoods are highly, or in some cases entirely, dependent on livestock. Animals are culturally, socially and economically vital in the region. Livestock provide, for example, over 60% of agricultural GDP in the Horn. Livestock are also a source of human disease.