3.7 Examination of the respiratory system
Auscultation of the lung fields is an important part of the clinical examination of the horse with suspected cardiac disease. It is important to identify changes which may be a result of cardiac disease, particularly the presence of pulmonary oedema due to left-sided heart failure. More commonly, pulmonary disease will be a complicating factor in an animal with cardiac disease. Alternatively, the signs of respiratory disease may be mistaken for those of heart disease.In addition to auscultation, examination of the lower respiratory tract (LRT) should also include percussion to establish the extent of the lung fields and the presence or absence of pleural fluid or air. The upper respiratory tract (URT) should also be examined. A nasal discharge may indicate URT disease such as sinusitis, URT infection, pharyngeal dysfunction with associated dysphagia, or LRT conditions such as viral or bacterial infection or chronic obstructive puldisease. Laryngeal dysfunction due to recurrent laryngeal neuropathy is a very important cause of poor athletic performance and palpation of the larynx should form part of a routine clinical examination. Endoscopy is extremely useful for evaluation of both the upper and lower respiratory tract and clinicians who expect to see animals with suspected cardiac disease need to become familiar with the technique.
3.7.1 Auscultation of lung fields