Fever and leukocytosis responses in goats to inhaled endotoxin are dose-dependent

Forty-five, weanling goats of mixed-sex, were randomly allotted to five treatment groups: no dust (n= 16), raw organic dust exposure for 15 min (n=6), raw organic dust exposure for 1 h (n=7), raw organic dust exposure for 3 h (n=7), and raw organic dust exposure for 4 h (n=9). Inhalation exposures were performed in a closed tent for the allotted times. The amount of endotoxin calculated to be in the dust was shown to be 26.9 mu g/g. The amounts of dust introduced into the tent for each time period were 4.58 g/m(3) of air for 15 min; 7.46 g/m(3) of air for 1 h; 14.82 g/m(3) of air for 3 h; and 40.60 g/m(3) of air for 4 h. There was a significant increase in the white blood cell count in the animals dusted for 4 h, at 8 and 12 h following exposure. There was a significant decrease in the peripheral lymphocyte cell count following the 15 min exposure at 12 h post exposure, and there was a significant increase in the peripheral lymphocyte cell count following the 4 h exposure, 24 h after the exposure. There was a significant increase in the neutrophil cell count 8 and 12 h following the 4 h exposure, while there was a significant decrease in the neutrophil cell count 48 h following the 4 h exposure. There was a significant increase in the rectal temperatures of all goats receiving the 4 h dust exposure at all time periods (0 time, 4, 12, 24, and 48 h). There was a significant increase in the rectal temperatures of goats following the 1 h exposure, 8 h later. These results indicate that the larger the dose of inhaled endotoxin, the higher the resultant fever and leukocytosis. Published by Elsevier B.V.