Equine asthma is an umbrella term to cover previously diagnosed conditions of inflammatory airway disease and recurrent airway obstruction. It is a non-infectious inflammatory disease of the lungs of horses and a lifelong condition for individual horses. The role of infectious diseases in equine asthma is still under review.
Source: Veterinary Advantage, February 2021. Link.
Because asthma is caused by factors in the environment, the most important treatment is to modify the horse’s environment to lessen exposure to whatever inhalant particles are triggering the horse.”
Also see: Search results for equine asthma, Animal Health Digest. Link.