Little has changed in the way lower airway disease is diagnosed in the last twenty years.

A comprehensive history taking followed by a thorough clinical examination should lead the clinician down logical diagnostic pathway. It is important to rule out other causes of coughing and dyspnoea, especially in older animals where there may be concurrent disease.

The mainstay of diagnosis still revolves around radiography in companion animals, followed by endoscopy with bronchoalveolar lavage. The harvested alveolar fluid is submitted for culture and cytology.

The increasing affordability of small diameter endoscopes brings bronchoscopy within the reach of most small animal practioners and most diagnosis is performed in the first opinion clinic.

Haematology and biochemistry profiles may also be performed but are often unrewarding.

Pulmonary function tests are rarely employed at present, being limited to specialist referral centres, yet their use is routine and regarded as crucial in the assessment of chronic respiratory disease in humans.

Further information on diagnostics and findings can be found in the extensive reference section.