A review of ‘equine asthma’, a term covering a range of respiratory diseases in horses, suggested that the recent rise in recorded veterinary incidence and severity may be due to increased time spent indoors, in enclosed stables and riding arenas, where airborne dust concentrations are high.
Many airborne particulate components identified could be lung irritants or allergens, including moulds, mites and bacterial endotoxins. Activities such as cleaning or ‘mucking out’ can produce high PM concentrations, persisting for hours after the activity is stopped, and the review advises that these activities should be carried out while horses are not present.
Proper consideration of ventilation and design, flooring, bedding and feed material, reducing the number of horses active in indoor spaces e.g. riding arenas at any given time, and the wetting of ground surfaces and forage can reduce airborne concentrations.