BAL is necessary to diagnose diseases such as chronic bronchitis, bacterial pneumonia (type and susceptibility of bacteria), eosinophilic bronchopneumopathy, lung worms (when not detected on feces), feline asthma, and useful in the diagnosis of foreign bodies that were not visible during bronchoscopy. Foreign body is suspected depending on the type of bacteria present in the sample.
BAL done via bronchoscopy offers the opportunity to choose the most affected area for sampling. This eliminates the possibility of not acquiring a representative sample during airway wash.