Comparisons of tracheobronchial (TBW) and bronchoalveolar wash (BAL) cytologies, using respectively 25 and 5 normal horses were made. Differential cell counts were made on both TBW and BAL fluids on Rosenfeld-stained cytocentrifuged preparations. Macrophages were the predominant cell types seen in both fluid samples and these findings suggest the possibility of an adequate sampling of the distal air passages. Differences were found in lymphocytes and macrophages between TBW and BAL cytologies. The main cell types in BAL fluids were macrophages (54.78±15.92%) and lymphocytes (33.70±14.41%). On the other hand, lymphocytes and macrophages were found in 2.91±3.44% and 81.51±11.06% of cell types in TBW fluids, respectively. Also, there were absences of epithelial and goblet cells in BAL cytology, and these explain the adequacy of the lower respiratory tract sampling, performed without causing trauma of proximal air passages. Other cell types were found in few numbers and no differences were found between TBW and BAL fluids. Differences were not detected concerning morphological characteristics between TBW and BAL preparations.
Horse; cytology; respiratory system; bronchoalveolar wash; tracheobronchial wash
