Recurrent Airway Obstruction (RAO) in Horses

strain of breathing
Flared nostrils
Tachypnea breathing more rapidly than normal
Wheezing or rattling sounds when breathing
Weight loss
Lack of appetite
Initially horses with RAO tend to experience symptoms only when exercising. However horses with more severe disease display symptoms even when at rest. These horses have a persistent cough and often heave their sides in and out with the effort of breathing. Youll notice that your horses nostrils are flared which is an attempt to draw in air more easily and the animal is breathing rapidly. Often theres a yellowish nasal discharge as well. Your horses ability to exercise or work will greatly diminish as the disease progresses.
Horses with severe RAO may lose weight due to a lack of interest in eating. However a fever is not a normal symptom of this disorder. Development of fever usually indicates a secondary bacterial infection often pneumonia 1
Causes of Recurrent Airway Obstruction
Recurrent airway obstruction in horses is similar to asthma in humans and is believed to be an allergic response to inhaled antigens primarily dust mold spores hay and straw. When the horse inhales these common allergens its airways respond by clamping shut bronchospasm narrowing bronchoconstriction and secreting mucus.
There also may be a hereditary component that contributes to a horses likelihood of developing RAO as horses with afflicted parents are far likelier to develop the disorder than horses with healthy parents 2
Diagnosing RAO in Horses
Generally an equine veterinarian can diagnose recurrent airway obstruction based on the horses characteristic symptoms and history. At times however your vet might want to do further testing to establish the diagnosis or rule out other causes of a chronic cough. One such test is a bronchoalveolar lavage which involves passing a tube into the horses lungs washing the lungs with a saline solution and then suctioning the saline back out again. This provides a sample of cells from the horses lungs as well as the secretions within the airways. Testing this sample can reveal the presence of infection andor inflammatory changes in the cells 1
Occasionally your vet might order xrays of the horses chest particularly if there is a concern that the horse has pneumonia or a secondary infection as well as RAO.
Treatment
Unfortunately recurrent airway obstruction is a chronic disease that can be managed but not cured. The mainstay of treatment for RAO is to remove the horse as much as is feasible from the allergy triggers. That means letting a stabled