Horses with equine asthma suffer from inflammation and/or obstruction of the lower airway so are unable to breathe as well as a healthy horse. An accumulation of excessive mucus in their airways causes them to cough from time to time and affects their ability to exercise, while severe cases show a clear increased effort to breath while at rest, commonly referred to as heaves.
This condition, which has previously been described as chronic obstructive pulmonary disease (COPD), is now widely referred to within the veterinary community as ‘equine asthma’ as research has shown it is more closely aligned to this condition in humans than it is to COPD, which is typically caused by chronic smoking or exposure of the human lungs to other damaging substances.
Equine asthma1 can be mild to moderate, when it is termed inflammatory airway disease (IAD), or severe, when it is described as recurrent airway obstruction (RAO). IAD is typically seen in young to middle aged horses, although it can be found in horses of any age. RAO is most often seen in horses over seven years of age.
Signs of equine asthma
In mild to moderate cases (IAD) a horse will cough occasionally both at rest and during exercise for four weeks or more and a loss of performance will be seen.