The highest exposures to these mould spores are associated with bedding that has been processed, packaged or baled damp and with deep litter management. The moulds that thrive in this high moisture and heat are very prolific. The spores from these moulds are very small and when inhaled can travel deeply into the lungs. Ammonia Ammonia is an irritant and is a recognised concern of stable management. The source of ammonia is the horse's urine and faeces.
Ammonia is released by the action of bacteria that degrade organic matter.
Ammonia inhibits the ability of the defence mechanisms in the airways to remove particles from the lung. Ammonia can also increase mucus production. Ammonia can be particularly high when stalls are being mucked out. If the horse is left in the stall during mucking, it will be subjected to high levels of ammonia and high levels of dust. The more absorbent a bedding is, the lower the levels of ammonia will be.