Headshaking in Horses | Help & Advice | Houghton Country

‘Headshaking’ describes the horse tossing its head up and down, often combined with excessive snorting, tick-like movements of the head, attempting to bury the nose into the ground or an object, striking out at the face, and rubbing the face and specifically nostrils on the legs or on objects. The horse can exhibit these signs both during ridden work and at rest, in the field and stable, but may only headshake in certain environments or at specific times. In many cases, exercise exacerbates the headshaking. Does this sound like your horse? It may be that you own a headshaker.

Horses have shown signs of what we now term as headshaking throughout the history of their domestication, but these signs have long been written off as behaviour, and even today many riders will be encouraged by their instructors to ignore and ride through headshaking from their horse. Believing headshaking to be behavioural means there has been little consideration given to the cause and therefore treatment of these signs. It is only in the last decade that seminal veterinary research has brought to light that headshaking without an obvious cause, like injury to the face, is likely caused by neurological facial pain rather than being behavioural.

This facial pain comes from a nerve that runs from the temporomandibular joint (TMJ) (where the end of your browband sits) to the nostrils and end of the muzzle, called the trigeminal nerve. This nerve can cause the horse to feel sharp, shooting pain. It does not appear that the horse feels this pain all the time – it is intermittent with the nerve firing pain signals sporadically, which presents in the horse as sudden tick-like movements of the head.

There can be other causes of headshaking, but a large percentage of horses that present to the vet with signs of headshaking stop exhibiting these signs when the trigeminal nerve is temporarily blocked, meaning it temporarily cannot cause pain. The fact these horses stop exhibiting signs of pain when this nerve cannot cause pain indicates that the cause of the headshaking is pain from the trigeminal nerve. If the horse was to continue headshaking with its trigeminal nerve blocked, that would indicate the cause of headshaking is something else. It has historically been very difficult to determine what causes headshaking in horses, with ones with the cause undiagnosed termed as idiopathic headshakers, but it is now understood that idiopathic headshaking is likely what we now term trigeminal-medicated headshaking.

Even with the information that the horse is headshaking due to the trigeminal nerve causing facial pain, it can be difficult to establish what is causing this nerve to irritate the horse. Common causes for headshaking in horses caused by the trigeminal nerve include a pollen sensitivity, and if this is the case for your headshaker, you are likely to see them displaying signs more frequently or severely when the pollen count is high, or around certain plants. For these horses, a nose net such as those attached to the noseband of the bridle can offer significant relief while the horse is being ridden. For time in the field, a fly mask with a nose covering that covers the nostrils is likely to offer some relief. Anecdotally, the difference a nose net can make to a headshaking horse is huge, as so many headshakers are affected due to pollen sensitivity. If your horse is showing signs of headshaking, a nose net will be worth trying as your first port of call to rule out a pollen sensitivity. If you conclude that this is the cause of your horse’s headshaking, consult your vet about treatment to manage the headshaking which can include antihistamines under prescription, keeping your horse stabled indoors during daylight hours or on days of a high pollen count, and respiratory supplements and/or medication if necessary. Applying Vaseline around the nostrils can also help. 

Of course there can be many other causes of headshaking in horses, including injury to or inflammation of any part of the face, light sensitivity, and dental problems, to name but a few. In these cases, the horse’s headshaking is not likely to appear to be linked to the weather or time of year, with the horse perhaps showing signs of headshaking year-round or temporarily after injury. In these cases, it is best to seek veterinary guidance as to how best to diagnose and then treat the cause of headshaking in these horses. 

Occasional headshaking in horses is within what we view as normal equine behaviour, but when the headshaking is frequent and is accompanied by signs of irritation such as rubbing the face, snorting and sneezing, or tick-like jerks of the head, the horse exhibiting these signs would be described as a headshaker. There are ways to manage headshaking in horses depending on the cause behind the headshaking, and the most challenging thing about the condition is probably getting the cause diagnosed and the best treatment plan in place. If your horse shows signs of headshaking, consult with your vet to start to try to determine the cause, and if the headshaking is more prevalent in the spring and summer months, a nose net and pollen supplements are worth trying to help to provide your horse with some relief.

Interested in the recent research into headshaking? Veronica Roberts’s 2019 publication pulls together recent developments in research into headshaking in horses.