Fortunately, horses have a limited number of diseases that can be transmitted to humans under natural circumstances. However, due to the close contact of horses with many people as work, exhibition or companion animals, human exposures to horse diseases can be more numerous than for other large animals. Some equine zoonoses are significant and emerging, such as Hendra virus, while others are well known: anthrax, rabies and salmonellosis. International and national transportation of horses for competition and sales also require steadfast testing and surveillance of equine infectious diseases to reduce the risk of spread. This chapter will review the zoonotic diseases of horses that can spread to humans via natural exposure: