− | Environmental control to reduce allergen exposure is key to the management of recurrent airway obstruction, as signs will re-appear following discontinuation of medication if this is not implemented. Since dusts in hay and straw are the most common triggers for disease, animals should be kept at pasture if possible. The availability of fresh grass eliminated the need for hay, and supplementary feeding can be achieved with pelleted feedstuffs. Round bale hay should not be provided as it is particularly allergenic and can cause environmental control to fail<sup>merck</sup>. If turn-out is not possibly, for example due to weather conditions, stalled horses should be maintained in a clean, controlled environment. Complete feeds may be fed that totally eliminate the need for roughge, although some horses prefer hay cubes or hay silage, which are equally acceptable. Soaked hay should not be fed as dust is incompletely removed and the nutritional content is poor. Shavings, newspaper or peat rather than straw should be used to bed animals, and supplies of hay and straw should not be kept in the same building as a RAO-afflicted animal. The addition of good ventilation to the stable design is also helpful if feasible. For example, a louvered vent may be added at the back of the stable, and the top door kept permanently open. | + | Environmental control to reduce allergen exposure is key to the management of recurrent airway obstruction, as signs will re-appear following discontinuation of medication if this is not implemented. Since dusts in hay and straw are the most common triggers for disease, animals should be kept at pasture if possible. The availability of fresh grass eliminated the need for hay, and supplementary feeding can be achieved with pelleted feedstuffs. Round bale hay should not be provided as it is particularly allergenic and can cause environmental control to fail<sup>merck</sup>. If turn-out is not possibly, for example due to weather conditions, stalled horses should be maintained in a clean, controlled environment. Complete feeds may be fed that totally eliminate the need for roughge, although some horses prefer hay cubes or hay silage, which are equally acceptable. Soaked hay should not be fed as dust is incompletely removed and the nutritional content is poor. Shavings, newspaper or peat rather than straw should be used to bed animals, and supplies of hay and straw should not be kept in the same building as a RAO-afflicted animal. The addition of good ventilation to the stable design is also helpful if feasible. For example, a louvered vent may be added at the back of the stable, and the top door kept permanently open. Some horses will be controlled by environmental management alone. |
− | Bronchodilators are used to counteract the broncho spasm | + | When medical therapy is neccessary, bronchodilators and corticosteroids are used. Bronchodilators, such as clenbuterol, are used to relieve bronchospasm in an attempt to minimise respiratory distress. Since mucus accumulation and inflammatory changes in the airway wall contribute to obstruction as well as bronchospasm, complete resolution may not be seen<sup>allen</sup>. Atropine is the best "rescue drug" in the event of severe respiratory disress. |
− | Medical treatment consists of a combination of bronchodilating agents (to provide relief of airway obstruction) and corticosteroid preparations (to reduce pulmonary inflammation). Bronchodilator therapy will provide immediate relief of airway obstruction until clincal signs of disease are controlled by corticosteroids. Severely affected horses are ideally controlled with aerosolized bronchodilators and systemic corticosteroids. Horses with mild to moderate airway inflammation can be treated with aerosolized corticosteroids and bronchodilators. It is inappropriate to treat RAO with bronchodilators as the sole therapy. NSAID, antihistamines, and leukotriene-receptor antagonists have failed to demonstrate therapeutic benefit.
| + | NSAID, antihistamines, and leukotriene-receptor antagonists have failed to demonstrate therapeutic benefit. |