If you are lucky enough to own a horse, then no doubt you have witnessed on occasion the Flehmen Response. This is where the horse in response mainly to a certain smell will curl its upper lip back, raise his head and breathe in and out making strange snuffle sounds, they will usually hold the position for a few seconds, and there may even be clear watery discharge from the nostrils when they are finished.
I was asked recently what was this response called, and why the horse did it? I answered that it was closely linked to breeding, where the stallion will exhibit the behaviour when sniffing a mare to see if she is ready to mate, however, I really didn’t know just how amazing this response is.
What is the Function of the Flehmen Response?
Flehmen the word is derived from a German word, which means to bare the upper teeth and also has roots to an Upper Saxon German word which means to look spiteful, so that’s how this response got its strange name. The animal that exhibits the response with curl its upper lip up, baring the top teeth while raising the head and breathing in and out.
The response is seen in many mammals from horses to big cats, and yes it has links to breeding and reproduction. The mechanism of the response is to allow pheromones and certain smells to be pulled via a duct in the horses nasal passages into Vomeronasal Organ otherwise known as Jacobson’s Organ at the base of the Nasal Cavity. This is an accessory olfactory organ which means that it works similar to a reflex and when activated the scent goes straight to the ancient primal areas of the animals brains such as the amygdala and the hypothalamus, and will initiate an immediate response. This response is often link to breeding as when we see the stallion sniffing the in season mare, but is also seen when horse’s sniff other horses dung, and is witnessed much more often in foals, with colts exhibiting the behaviour more than fillies.
So why not introduce your horse to a new smell and see if you can get him to show you the Flehmen response, if he does it, it usually means he is storing that smell for future reference. Check out our YouTube Video Above Where we try to get our horses to show you the Flehmen Response 😉
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This Article was originally published in the December 2020 Issue of Irish Sport Horse Magazine.