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, cough (often productive), dyspnoea, increased expiratory effort and flared nostrils. Pyrexia is not usually a feature of SPA-RAO. In severe cases, affected horses 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. Lung field auscultation reveals fine crackles and wheezes. In severe cases, wheezes may be audible without a stethoscope.  

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, cough (often productive), dyspnoea, increased expiratory effort, nasal discharge and flared nostrils. Pyrexia may be a feature if a seconday bacterial infection has occurred in the airways. In severe cases, affected horses 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. Lung field auscultation reveals fine crackles and wheezes. In severe cases, wheezes may be audible without a stethoscope.  

==Diagnosis==

==Diagnosis==

Diagnosis is usually pased on the characteristic clinical signs combined with a history of seasonal occurrence and exposure to pasture during late spring or summer. If hay appears to act as a trigger to the horse, a complete pelleted diet may be fed or alternatively hay should be soaked. Alfalfa has been previously associated with less respiratory problems than grass hay and may be preferable.  

Diagnosis is usually pased on the characteristic clinical signs combined with a history of seasonal occurrence and exposure to pasture during late spring or summer. Endoscopy may be used in order to evaluate the airways and to examine the presence of inflammation or mucus. A sample of the mucus may be taken in order to perform bacterial culture or cytology.  

==Treatment and management==

==Treatment and management==

Affected horses should only be allowed access to pasture during late autumn, winter and early spring.

Affected horses should only be allowed access to pasture during late autumn, winter and early spring. If hay appears to act as a trigger to the horse, a complete pelleted diet may be fed or alternatively hay should be soaked. Alfalfa has been previously associated with less respiratory problems than grass hay and may be preferable.  

==References==

==References==

*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''