The prescience to measure airway reactivity in horses without heaves

Horses that exhibit reduced aerobic performance, mucus in the airways, and/or cough have long been discussed as a subgroup of COPD or more recently, 'inflammatory airway disease (IAD)'. Many highly aerobic horses such as racehorses and eventers with IAD, have no clinical signs at all other than a decline in performance, Hence more sensitive, objective tests for diagnosis are required, Highlighted here is a paper published by Klein and Deegen that demonstrated, way ahead of its time, the clinical utility of measuring airway responses to aerosolized histamine (non-specific airway reactivity). Although others before had applied the method in research involving horses with heaves, Klein and Deegen had the foresight to apply this method to the clinical population without heaves, presumably with IAD. Recent data has shown that horses with IAD (based on bronchoalveolar lavage cytology) have extremely high levels of airway reactivity to histamine. The test of airway reactivity, first reported in non-heaves horses by Klein and Deegen, will be an important diagnostic tool in the assessment of low-grade respiratory signs and poor performance in the future.