Equine pulmonary disease: a case control study of 300 referred cases. Part 2: Details of animals and of historical and clinical findings.

Examination of historical and clinical details of 270 adult horses suffering from a variety of mainly chronic pulmonary diseases showed that the chronic obstructive pulmonary disease (COPD) group (median age 9 years) were the oldest, and that the COPD, chronic idiopathic hypoxaemia and exercise induced pulmonary haemorrhage (EIPH) groups had the longest duration of disease (median durations 7, 12 and 9 months, respectively) with a median disease duration of 2 months for the remaining horses. A history of antecedent respiratory infection was present in 24.3% of all horses. Six out of 12 horses that grazed with donkeys suffered lungworm infection. Silage was fed to 11.3% of all horses, nonstraw beddings were utilised by 28.7% of horses and 8.7% of horses were maintained permanently outdoors. Environmental control had been unsuccessfully attempted in 47% of COPD cases prior to referral. Histories of poor athletic performance or of excessive post exercise dyspnoea were found to be less definitive indicators of pulmonary disease. Coughing was the most sensitive clinical indicator of pulmonary disease, being present in 71.1% of horses with pulmonary disorders. Nasal discharge was present in 50.4% of these horses and coughing or nasal discharge was present in 86.7% of horses with respiratory disorders. Unilateral nasal discharge was inexplicably present in 3.3% of horses with pulmonary disease. Other clinical findings, including the presence of increased breathing effort, abnormal thoracic or tracheal auscultatory findings were less sensitive diagnostic parameters with pulmonary diseases, and were frequently absent unless severe pulmonary disease was present.