Statistical evidence for a link between bronchopneumonia and disseminated focal nephritis in pigs.

An investigation on the occurrence of different pneumonia types and their possible concurrence with other pluck organ disorders was made on 6,565 pigs presented at slaughter. The frequency of disseminated focal nephritis in a bronchopneumonia group and a non-bronchopneumonia residual group, respectively, was found to differ significantly from the mean frequency of nephritis in all pig plucks examined. The number of lesioned kidneys in each of 28 samples contributing to the bronchopneumonia group and in each of 8 samples contributing to the residual group was regressed group-wise on the number of individual plucks examined in each sample; the correlation coefficient for each of these two groups was calculated. These calculations showed a highly significant link between bronchopneumonia and disseminated focal nephritis. The histopathological and bacteriological examination of some lung and kidney lesions representing the bronchopneumonia group substantiated this finding. It is concluded that the two diseases are connected through dissemination, and that Pasteurella multocida is the organism involved in the majority of cases.