Experimental infections enabled to test susceptibility of the goose and duck to M. avium. After intramuscular implantation of M. avium suspension, local lesions were observed at the spot of puncture in the geese, and miliary tuberculosis of spleen in 35 days, as well as miliary tuberculosis of liver after 69 days. In the ducks, local lesions were found at the spot of puncture in 35 days and miliary tuberculosis of liver and spleen in 69 days. Cultivation demonstrated mycobacteria in various tissues and organs since day 12 after infection. Peroral infection with contaminated feed caused lesions in spleen and intestine in the geese in 106 days, and then in liver and lungs in 133 days. The ducks had lesions in the intestine in 106 days, and in liver and spleen in 133 and 136 days, resp. Cultivation proved sporadic mycobacteria in liver, spleen, lungs and/or bone marrow and brain in both species. No tuberculous lesions were observed in the geese or ducks within 253 days of the experiment after infections by contacts with the TBC fowl. Cultivation demonstrated sporadic mycobacteria in liver, spleen, kidneys, lungs and bone marrow. The goose and the duck are very resistant to M. avium infection. The duck seems to be less susceptible than the duck.