The late Charles Henry Stange. said, "During the past fifteen years, the prevention and control of the infectious diseases of animals has become a state and national problem, the work being organized on the basis of state and national cooperation. Livestock owners have available to them much information concerning animal diseases and the public is becoming increasingly conscious of the possibilities of disease transmission from animals to man. At present, there is little information available in the epidemiology of the contagious diseases of animals which would make their successful control and eradication very much easier. In the midst of the transition period in which we now find ourselves, it is apparent that veterinarians need considerable information, much of which may seem of a diverse nature, but all having a significant bearing on the most important problem confronting the veterinary profession today viz., disease prevention and control."