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

This research studied the history and clinical symptoms of 270 adult horses suffering from various types of mainly chronic lung diseases. The findings revealed that horses with chronic obstructive pulmonary disease, chronic idiopathic hypoxaemia, and exercise-induced pulmonary haemorrhage had the longest disease durations. Coughing was found to be the most reliable indicator of pulmonary disease in horses.

Objective and Approach

• This study examined the historical and clinical details of 270 adult horses suffering from primarily chronic lung or pulmonary diseases. By doing so, it aimed to understand and provide insight into the occurrence, and progression of these diseases in equine populations.
• The cases studied included horses suffering from chronic obstructive pulmonary disease (COPD), chronic idiopathic hypoxaemia and exercise-induced pulmonary haemorrhage (EIPH), among others.

Findings

• A key finding of this study was the different disease durations across groups. COPD, chronic idiopathic hypoxaemia, and EIPH resulted in the longest disease durations, with median durations of 7, 12, and 9 months, respectively. The remaining horses had a median disease duration of 2 months.
• According to the study, 24.3% of all horses had a history of preceding respiratory infection, and 12 horses that grazed with donkeys suffered lungworm infections.
• Several horses’ habits were noted, including feeding with silage (11.3% of horses), utilizing non-straw beddings (28.7%), and staying permanently outdoors (8.7%). In 47% of COPD cases, efforts to control the environment were unsuccessful.

Diagnostic Parameters

• The research indicated that coughing is a sensitive clinical indicator of pulmonary disease, listed in 71.1% of diagnosed horses. Other observed symptoms included nasal discharge (found in 50.4% horses), and either coughing or nasal discharge was present in 86.7% of horses with respiratory disorders.
• The study also found that unilateral nasal discharge was inexplicably present in 3.3% of horses with pulmonary disease. Other significant clinical findings were increased breathing effort and abnormal thoracic or tracheal auscultatory findings. However, these were less reliable diagnostic parameters, and were often absent unless the pulmonary disease was severe.