Horse & Hound
A natural filter
THE respiratory system prevents harmful substances entering a horse’s lungs…
1 Hairs inside the nostrils obstruct larger particles.
2 Humidification in the nasal sinuses and pharynx moistens particles, making them heavier and stickier.
3 The conchal sinuses generate a swirling airflow that drives medium-sized particles into the mucuscovered sinus linings.
4 In the pharynx, which acts as a holding chamber where air pauses between each breath, particles sink or spread to the sides and become trapped by mucus.
5 The trachea (windpipe) speeds up airflow. This sweeps remaining particles on to its mucus-covered sides, where multiple cilia
(tiny hairs) transport them back up to the pharynx to be swallowed or snorted away.
If a horse is placed in an environment that overwhelms this natural filtering, airway inflammation and mucus accumulation can result.