Haematological changes associated with Aspergillus fumigatus infection in experimental mycotic abortion of sheep.

The haematological changes specifically associated with infection were studied in experimentally inoculated pregnant sheep. No significant changes in relation to infection were observed in the haemoglobin concentration, erythrocyte sedimentation rate, packed cell volume, mean corpuscular haemoglobin concentration or erythrocyte morphology of inoculated sheep. There was little evidence of changes in total leucocyte count in most sheep in the first few weeks following inoculation, although those animals receiving larger inocula showed signs of an increasing leucocytosis at the terminal phase of gestation. This increase was even more pronounced at the time of lambing or abortion. Compared with uninoculated pregnant controls, the mean relative neutrophil counts of the inoculated sheep tended to increase during the later stages of gestation and showed highly significant increases at the time of lambing or abortion. Both total leucocyte and relative neutrophil counts were significantly higher in those sheep showing signs of placental infection than in those inoculated animals with no evidence of placentitis. There was some evidence of a relationship between the dose of conidia inoculated and the severity of infection as indicated by the number of animals aborting, extent of placental involvement and reduction in mean gestation period. Irrespective of inoculum size, only a proportion of inoculated animals developed detectable placentitis.