Transtracheal aspiration technique in diagnosis of lower respiratory tract disease in the cow

In present study the transtracheal aspiration technique using a commercial polypropylene 5 fr. urinary catheter with 13-gauge 2.5 inch hypodermic needle was applied to bovine medicine in order to determine the availability of this procedure for diagnosis of lower respiratory tract disease. The subjects were forty adult cattle which consisted of thirty-one cows with respiratory signs such as cough and nasal discharge and nine cows without these signs. This procedure appeared suitable for collecting specimens of the lower respiratory tract secretions without uncontamination by the flora of the mouth, respiratory distress and any complications. The most of microorganisms isolated was Pasteurella multocida (48.7 %) and a mucopurulent inflammatory response was the most appeared accounting for 40 % of cytological basis. Most cows with severe clinical signs showed a mucopurulent inflammation (60 %) and Pasteurella multocida were isolated dominantly in severe cases (63.2 %). Cows with mild clinical signs were distributed in each of the five cytological classification and Pasteurella multocida was the most isolated accounting for 40 % of mild cases. In the cytologic examination, a few neutrophils and epithelial cells were seen in the fluid of mucoid inflammation, and many neutrophils with epithelial cells and thick mucoid exudate were seen in the fluid of mucopurulent inflammation. Various number of neutrophils, lymphocytes, macrophages and epithlial cells were examined in the fluid of mixed cell inflammation. The columnar ciliated epithelial cells were examined mainly in normal aspirates. From these results the transtracheal aspiration technique as a diagnostic aid for lower respiratory tract disease of cow is considered as a simple, safe and useful method and can be performed in the field situation