The role of wild birds and their ectoparasites (ticks) in the circulation and distribution of M. avium and possible formation of natural foci of avian tuberculosis.

The leading role of wild birds in the spread and circulation of the causative agent of avian tuberculosis is emphasized and the basic theoretical prerequisites of developing the hypothesis of the formation of its natural foci are discussed. The significance of the individual factors for the formation of the theory of natural foci of tuberculosis caused by M. avium is displayed. The opinion is expressed that avian tuberculosis should be classified among facultatively transmissible natural-focal infections in the epizootic process of which both transmissive (ticks) and non-transmissive (water; various infected substrates, soil, etc.) factors take part.