|First Posted: Oct 28, 2009|
Jan 10, 2014
Yawning in Horsesby Debora Johnson
Yawning horse: Permission given for image use by my dear friend, Frank.
We have all seen our horses yawn. Why does a horse yawn? That is a good question. In fact, it is not really known why horse yawn. Some suggestions for this behavior are the following:
*The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system.
The trigeminal nerve distribution in the horse's head. The three branches of the trigeminal are shown (ophthalmic (1 st), maxillary (2 nd) and mandibular (3 rd)). Adapted from Goody, P (2000) Horse anatomy: a pictorial approach to equine structure 2 nd Ed. J.A. Allen Publishers, London. From Taylor, K. (2004) PhD Thesis, De Montfort University, Leicester.
"About the only thing we're fairly sure of is that the trigger is not the same as that of a yawn in humans, which is in response to transient drops in blood oxygen levels. That big intake of fresh air increases oxygen in the lungs and therefore in the vascular system. However, horses do not appear to be inhaling when they 'yawn.'" What Makes a Horse Yawn? - by: Mary DeLorey, DVM
The only certainty is that horses do yawn!