Comparison of bacteria isolated from lower airway fluids obtained by transtracheal route or bronchoalveolar route in calves

The lower respiratory tract secretions can be useful in identifying microbi al pathogens in case of pneumonia in calves. The transtracheal aspiration i s the most frequently used technique to obtain these specimens but it is co nsidered as traumatic (possible subcutaneous injuries). To avoid these comp lications, a simple and safe broncho-alveolar ravage technique, with obliga tion passage of the tube through the upper airways, was used and the result s of bacteriologic culture of lower airway fluids obtained by use of both t echniques were compared. The results obtained show that with a contaminated broncho-alveolar lavage fluid, the corresponding transtracheal aspiration fluid was either negative or bacteriologically less charged in 71% of the c ases. These results clearly show that broncho-alveolar lavage are more cont aminated that corresponding transtracheal aspiration. Thus, the broncho-alv eolar ravage method by nasotracheal way does not reflect the real bacteriol ogical pattern of the lower respiratory tract.