Laboratory Evaluation of Transtracheal Wash (TTW) in Buffaloes Affected with Lower Respiratory Tract Infections

Background- Evaluation of transtracheal wash (TTW) has been proved beneficial in the diagnosis and understanding the pathology of lower respiratory tract infection in species like equines and dogs. However, its diagnostic potential in buffaloes has not been explored much. This study elucidated the cytological and microbiological features of TTW in buffaloes. Methods- TTW was collected from 36 buffaloes (26 diseased and 10 healthy control) after adequately restraining and using baby feeding tube after giving a small stab incision at ventral neck region. After collection, TTW were subjected to cytological studies following staining with Leishman stain. TTW was also sent aseptically to laboratory for bacteriological culture. Results- The lower respiratory tract affections like aspiration pneumonia, suppurative pneumonia, fibrinopurulent pneumonia, chronic pneumonia and tuberculous pneumonia were diagnosed based on cytology of TTW in correlation with history and comprehensive clinical examination. The mean cell number (cells/HPF) in TTW of diseased buffaloes were significantly higher than control groups. In control groups, the predominant cells were alveolar macrophages followed by neutrophils, epithelial cells, lymphocytes and other cells which includes mast cells, fibroblasts and unidentified nucleated cells. Neutrophils were the predominant cells followed by macrophages in TTW of buffaloes diagnosed with suppurative, fibrinopurulent and aspiration pneumonia, whereas, alveolar macrophage were predominant in TTW of chronic pneumonia and tuberculous pneumonia affected animals. Four out of ten TTW samples from healthy animals were evidenced bacterial growth in which Staphylococcus spp. was the predominantly isolated bacteria. TTW samples from 20 out of 26 diseased buffaloes were found positive for bacterial culture from which a total of 30 bacterial isolates were obtained which include Staphylococcus aureus, Klebsiella pneumonia, Pasteurella multocida, Streptococcus spp., E. coli and Bacillus spp. Thus, TTW provides vital information about the ongoing pathogenesis in respiratory tract infection. It is suggested that, cytological and bacteriological culture of TTW samples should be carried out during the diagnosis and therapeutic intervention of respiratory tract infection in buffaloes.