Occurrence: Worldwide. Species affected: All. Age affected: Older (over 2 years of age), rare in commercial flocks.

Causes: Bacterium- Mycobacterium avian.

Effects: Pale, regressed combs and wattles, depression, emaciation, anaemia, unthriftiness, icterus (yellow skin) and lameness. Public health significance.

Avian tuberculosis can be a serious chronic problem in older birds (over 2 years of age) of all species, but in ...