According to Website's International Dictionary (second edition, 1953), "Zoonosis" is defined either as a disease communicable from animals to ech other or to man, or as disease due to animal parasites. In a board sense this inclusive definition may be applied to almost any communicable disease of animals, regardless of whether it is transmissible to man. However, FAO and WHO expert committee in 1959 defined zoonoses as "those disease and infections (the agents of) which are naturally transmitted between (other) vertebrate animals and man.