Respiratory Diagnostic Tests

Sampling of airway secretions for cytological analysis and microbial culture are invaluable for proper diagnosis of respiratory disease and to help guide therapy in affected horses. The most common sampling techniques are tracheal wash and bronchoalveolar lavage (BAL). Tracheal wash sampling is recommended when a respiratory infection is suspected (bacterial or fungal). If non-infectious respiratory disease is suspected (e.g. asthma, exercise-induced pulmonary hemorrhage), sampling of respiratory secretions using BAL technique is preferred.

Video 1: Demonstration of tracheal wash technique using a transcutaneous (through the skin) approach. It is the most economical method however, it carries a risk of abscess formation at the puncture site on the neck because of seeding of tissue with bacteria as the sampling catheter and needle are withdrawn.

Video 2: Demonstration of tracheal wash technique using an endoscope and specialized catheter. Both tracheal wash techniques (endoscope and transcutaneous) are considered equivalent regarding test results expected. The endoscope technique does not carry the risk of neck infection since no skin puncture is required.

Video 3: Demonstration of bronchoalveolar lavage (BAL) using a “bling” technique with a BAL catheter.

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