Changes

==Clinical signs==

==Clinical signs==

Clinical signs are similar to those associated with RAO but occur in horses kept out at pasture during the summer months, usually for more than twelve hours a day. Signs may include exercise intolerance, productive cough, dyspnoea, increased expiratory effort, nasal discharge and flared nostrils. Lung field auscultation reveals fine crackles and wheezes. In severe cases, wheezes may be audible without a stethoscope. Pyrexia may be a feature if a secondary bacterial infection of the airways has occurred. Affected horses may stand with their neck arched and elbows abducted. An abdominal 'heave' line may also be visible due to hypertrophy of the external abdominal oblique muscles.  

Clinical signs are similar to those associated with RAO but occur in horses kept out at pasture during the summer months, usually for more than twelve hours a day. Signs can include exercise intolerance, productive cough, dyspnoea, increased expiratory effort, nasal discharge and flared nostrils. Lung field auscultation reveals fine crackles and wheezes. In severe cases, wheezes may be audible without a stethoscope. Pyrexia may be a feature if a secondary bacterial infection of the airways has occurred. Affected horses often stand with their neck arched and elbows abducted and an abdominal 'heave' line may be visible due to hypertrophy of the external abdominal oblique muscles.  

==Diagnosis==

==Diagnosis==

Diagnosis is usually based on the characteristic and seasonal appearance of clinical signs combined with a history of exposure to pasture during late spring or summer. Endoscopy may be used in order to examine the airways for the presence of inflammation or mucus. A sample of mucus may be obtained via bronchioalveolar lavage which often yields copious mucupurulent material. Cytology performed on the sample usually reveals >25% non-degenerate neutrophils confirming the presence of lower airway inflammation. Curschmann's spirals may also be observed, representing inspissated mucus in the obstructed lower airways.  

Diagnosis is usually based on the characteristic and seasonal appearance of clinical signs combined with a history of exposure to pasture during late spring or summer. Endoscopy may be used in order to examine the airways for the presence of inflammation or mucus. A sample of mucus can be obtained via bronchoalveolar lavage which often yields copious mucopurulent material. Cytology performed on the sample usually reveals >25% non-degenerate neutrophils confirming the presence of lower airway inflammation. Curschmann's spirals may also be observed, representing inspissated mucus in the obstructed lower airways.  

Thoracic radiology is not commonly performed but may reveal an increased bronchointerstitial pattern.

Thoracic radiology is not commonly performed but often reveals an increased bronchointerstitial pattern.

==Treatment and management==

==Treatment and management==

*McGorum, B. C., Edward Robinson, N., Dixon, P. M., Schumacher, J. (2007) '''Equine respiratory medicine and surgery''' ''Elsevier Health Sciences''   

*McGorum, B. C., Edward Robinson, N., Dixon, P. M., Schumacher, J. (2007) '''Equine respiratory medicine and surgery''' ''Elsevier Health Sciences''   

*Orsini, J. A., Divers, T. (2007) '''Equine Emergencies: Treatment and Procedures''' ''Elsevier Health Sciences''

*Orsini, J. A., Divers, T. (2007) '''Equine Emergencies: Treatment and Procedures''' ''Elsevier Health Sciences''

[[Category:Allergic Respiratory Diseases]][[Category:Horse]][[Category:To Do - Blood]][[Category:To Do - SophieIgnarski]]

[[Category:Allergic Respiratory Diseases]][[Category:Horse]][[Category:To Do - Blood]][[Category:To Do - SophieIgnarski]]