Bronchoscopy and bronchoalveolar lavage (BAL)

What it involves

Bronchoscopy is the passing of a thin, flexible endoscope through the larynx into the trachea and bronchi. On the screen we assess the movement of the larynx, the shape and rigidity of the trachea (collapse), the appearance of the bronchial lining, and the presence of secretions, foreign bodies, tumours or parasites. It is the only examination that shows the airways “live”, during breathing.

Bronchoalveolar lavage (BAL) involves passing a small amount of sterile saline through the endoscope into a chosen bronchus and immediately aspirating it, together with cells and secretions from the alveoli. We examine the fluid obtained cytologically in our laboratory (inflammatory cells, eosinophils, tumour cells, parasites) and send it for bacterial culture with an antibiogram and, if needed, for PCR.

The result: a specific diagnosis instead of another round of antibiotics and steroids given “on a trial basis”. We perform the examination under brief general anaesthesia with oxygen supplied throughout.

When it is used

We recommend bronchoscopy for a cough lasting more than 4–8 weeks with no diagnosis, a cough that returns after medication is stopped, lung changes of unclear nature on X-ray, suspected tracheal collapse or laryngeal paralysis, suspected foreign body in the airways (for example a grass awn inhaled while running), and for feline asthma and chronic bronchitis before long-term treatment is started.

We perform the examination once the patient is stable — in an animal with severe breathing difficulty we treat first and diagnose when it is safe.

Indications: symptoms that should prompt a visit

• A dog has been coughing for several months, the X-ray is inconclusive, and antibiotics and steroids gave only temporary improvement.
• A cat has coughing fits with its neck stretched out and wheezing — suspected asthma.
• A small dog has a “goose-honk” cough when excited or pulling on the lead.
• A large, older dog has noisy breathing, a changed voice and tires in hot weather — suspected laryngeal paralysis.
• After running in grass, a dog suddenly began to cough and sneeze violently, and the symptoms have not gone away.
• The chest X-ray shows opacities or a nodule that cannot be sampled through the chest wall.
• The animal has recurrent pneumonia with no identified cause.

Conditions for which we use it in particular

Diagnostics beforehand

Before bronchoscopy we take chest X-rays in three views, a blood count and biochemistry, and for a heart murmur an echocardiogram — a cough of cardiac origin is treated differently from a lung cough and does not require endoscopy. A faecal test for lungworm (Baermann method) is sometimes a first, simple step in young animals.

Pre-anaesthetic assessment under STD-01 is particularly important here: a patient with airway disease is more sensitive to drops in oxygen saturation. We plan oxygen therapy before, during and after the examination, and in cats with asthma we give bronchodilators before the procedure.

How it proceeds

Aftercare

For 1–2 days the animal may cough a little more and be sleepy. Avoid exertion, excitement, hot weather and smoke. Give an easily digestible meal in the evening. If the cytology result is available the same day, we can start initial treatment straight away; culture and PCR come back in 3–7 days.

We discuss the result at a visit: we agree the treatment (an antibiotic chosen according to the antibiogram, inhaled medication with a spacer, antiparasitic drugs, weight reduction and a harness for tracheal collapse) and the follow-up schedule. Call immediately if breathing becomes laboured, the gums turn blue or a fever appears.

Frequently asked questions