Effect of repetitive bronchoalveolar lavage on cytologic findings in healthy dogs

Abstract

Objective - To determine reference values for cytologic examination results of bronchoalveolar lavage fluid (BALF) and to investigate effects of repeated lavages on pulmonary health and on results of cytologic examination of BALF in dogs. Animals - 16 healthy adult Beagles. Procedure - All dogs underwent pulmonary lavage to obtain BALF. Eleven dogs were repeatedly lavaged 6 times at 5-to 7-week intervals. Analyses for total and differential cell counts and for viability of cells before and after cell processing were performed. Arterial blood gas analysis before and after bronchoalveolar lavage was used to study the safety of the lavage procedure. Histologic and radiologic examinations were used to study effects of repeated lavages on pulmonary health. Results - Mean (± SD) cell count was 104 ± 69 cells/μl, comprising 75 ± 7% alveolar macrophages, 13 ± 6% lymphocytes, 5 ± 4% neutrophils, 4 ± 5% eosinophils, 2 ± 2% mast cells, 0.6 ± 0.7% epithelial cells, and 0.3 ± 0.4% plasma cells. Centrifugation of samples and washing of cells caused significant cell loss (59 ± 13%). Repeated lavages did not cause significant variations in cell counts of BALF or results of arterial blood gas analysis, thoracic radiography, or histologic examination of pulmonary specimens. Only a moderate, although significant, decrease in arterial oxygen content was observed after bronchoalveolar lavage. Conclusions and Clinical Relevance - Analysis indicated that several lavages performed at 5-to 7-week intervals can safely and reliably be used to study the kinetics of pathologic processes in pulmonary tissues or for evaluation of therapeutic efficacy.