The objective was to determine whether the inhalation of large quantities of feedyard dust predisposed the animals to pulmonary bacterial proliferation. Two control groups, C1 and C2, did not receive dust treatments, and two principal groups (P1 and P2) received a total of 14 dust treatments each. The CI and PI groups of goats each received a transthoracic challenge of live Mannheimia haemolytica (4 X 106 colony forming units, CFU) The C2 and P2 groups of goats each received a transthoracic challenge of live Pasteurella multocida (1.0 X 10(6) CFU/goat). The results showed that dusted animals had fever when compared with non-dusted controls. In addition, dusted animals demonstrated a leukocytosis with neutrophilia after the first dust treatment that was not sustainable. Finally, dusted animals demonstrated pulmonary clearance of two potential bacterial pathogens that was not significantly different from that shown by control (not dusted) animals.