Equine asthma: current understanding

Abstract

Equine asthma is the new term for lower airway inflammation in horses. This disease is further subdivided into mild to moderate asthma, better known as inflammatory airway disease (IAD), and severe asthma, better known as recurrent airway obstruction (RAO). RAO causes lower airway inflammation and obstruction resulting in chronic coughing, increased respiratory effort at rest and exercise intolerance, usually in horses over seven years of age. IAD, on the other hand, can occur at any age and the clinical signs are often much more subtle, namely reduced performance and occasional coughing. Equine asthma is mainly triggered by a high concentration of dust and mould spores in the stable environment or pollen during the summer months in the case of summer pasture associated RAO (SPARAO). To diagnose equine asthma, it is recommended to perform an endoscopy, followed by a bronchoalveolar lavage (BAL). Environmental control remains the principal treatment method, often in combination with the temporary administration of corticosteroids and bronchodilators.