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. 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.  

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.  

==Diagnosis==

==Diagnosis==

==Treatment and management==

==Treatment and management==

Control of environmental exposure is essential in horses affected by SPA-RAO. Affected horses should only be allowed access to pasture during late autumn, winter and early spring. They should ideally be kept stabled in a dust-free environment such as a stable with rubber matting and no bedding. If hay appears to act as a trigger to the horse, a complete pelleted diet may be fed or alternatively hay should be thoroughly soaked. Alfalfa hay has been previously associated with less respiratory problems than grass hay and may be a preferable source of roughage for affected horses. Horses with severely compromised respiratory function should be rested until their condition has improved.

Control of environmental exposure is essential in horses affected by SPA-RAO. Affected horses should only be allowed access to pasture during late autumn, winter and early spring. They should ideally be kept in a dust-free environment such as a clean stable with rubber matting and no bedding. If hay appears to act as a trigger to the horse, a complete pelleted diet may be fed or alternatively hay should be thoroughly soaked. Alfalfa hay has been previously associated with less respiratory problems than grass hay and may be a preferable source of roughage for affected horses. Horses with severely compromised respiratory function should be rested until their condition has improved.

In some cases, the response to environmental management may be significant and further treatment may not be required. In more severe cases, drug therapy may be required to suffiently manage the horse's condition. Corticosteroids (e.g. dexamethasone) may be administered via nebuslisation using an inhaler in order to produce the maximum concentration of the drug in the respiratory tract, with minimal systemic side effects. This treatment can be combined with a bronchodilator such as clenbuterol to reduce smooth muscle contraction in the lower airways. Antibiotics may be required if seconday bacterial infection is present.

In some cases, the response to environmental management may be significant and further treatment may not be required. In more severe cases, drug therapy may be required to suffiently manage the horse's condition. Corticosteroids (e.g. dexamethasone) may be administered via nebuslisation using an inhaler in order to produce the maximum concentration of the drug in the respiratory tract, with minimal systemic side effects. This treatment can be combined with a bronchodilator such as clenbuterol to reduce smooth muscle contraction in the lower airways. Antibiotics may be required if seconday bacterial infection is present.