Avian tuberculosis which occurred in an imported pigeon and pathogenicity of the isolates

A tubercular lesion (15 mm in diameter) was found on the skin of the caudal part of the cloaca in a 2-year-old male carrier-pigeon. Mycobacterium avium serovar 2 was isolated from the tubercular lesion on the skin and in the feces. The smooth and dome (SmD) variant (4.9 x 10(6) CFU) and rough and granular (RG) variant (3.7 x 10(7) CFU) of the isolates were injected into chickens intravenously. The chickens inoculated with the RG variant died on the 39th day and the one with the SmD variant died on the 77th day after inoculation. Enlargement of the liver and spleen was observed in all the inoculated chickens. Many white tubercular lesions were observed in the liver, spleen and lung of the chicken inoculated with the SmD variant, while no macroscopical change was observed in the bird inoculated with the RG variant. Inoculated organisms were recovered from the liver, spleen, kidneys, lungs and pancreas of each inoculated chicken.