It can get right down the trachea to the bronchi leading out to the lungs.  We can take samples and biopsies with tiny instruments that pass down the centre of the tube, which aid in diagnosis of disease.  We can also see any foreign objects, growths or signs of irritation or infection, or structural problems (such as collapsing tracheas) directly.

The small bronchoscope also fits perfectly down to the stomach of small dogs and cats, so we can identify problems with the oesophagus and stomach as well.   Bones wedged in the oesophagus are a frequent finding.

We also have a much larger endoscope suitable for doing similar diagnostic work in large dogs.