The Hardy Horse…
I currently have the ‘hard’ task of taking my kids to school skiing. Friday was an absolute stunner, but my fingers still swore at me if I touched the snow gloveless… this got me thinking of Horses standing happily with their hooves buried in snow. How do they do it?!
The lower half of the horse’s limbs are mainly bone and tendon – these tissues require much less blood for maintenance than muscle, and therefore, the horse can afford to divert a portion of the blood flow that was heading to the limbs back to the core. It does this opening nifty arteriovenous shunts, secret passageways between the arteries going to the limb and the veins returning to the heart.
Horses also have a physiological adaptation called countercurrent exchange, which is designed much like a heat transfer in your ventilation system – Veins and arteries run in parallel, allowing warmth of the arterial blood to transfer to the colder venous blood so that when the arterial blood reaches the hoof less heat is lost to the environment, but enough is retained to stop the foot from freezing.
In addition, the thick, dense hoof capsule protecting the inner tissues of the foot from that freeing snow... a bit like my gloves!
Written by our lovely part-time Vet Laura