Experimental production of amyloidosis in ducks.

Ducks repeatedly inoculated intravenously with crude extracts of Escherichia coli (Ec) or Salmonella typhimurium (St) or the mixture of crude extracts of E, coli and S. typhimurium (ES) developed amyloidosis. The total number of injections was 22 or 23 (Exp. 1) and 25 (Exp. 2), respectively. The initial doses were the lowest and then gradually increased to the study doses at 15th injection (Exp. 1) or at tenth inoculation (Exp. 2), respectively, which was maintained until the end of the experiments. The incidences of amyloid deposits in injected ducks were 9/30 (St1) and 15/30 (ES1) for the ducks that received the crude extract of ST or the mixture of crude extracts of ES in Exp. 1,16/40 (St2), 30/40 (Ec2) and 20/40 (ES2) for the ducks that received the crude extract of St, or the crude extract of Ec, or the mixture of crude extract of ES in Exp. 2, respectively. The results obtained suggest that the bacteria and their endotoxins seem to play a significant role in the pathogenesis of amyloidosis in ducks.