Everything You Need To Know About Headshaking: Causes, Symptoms, Diagnosis & Treatments

Headshaking in horses is an often misunderstood condition that can vary in severity from a mild, occasional headshake to a persistent and violent one that can make a horse dangerous to ride in some extreme cases. The good news though is that we’re learning more and more about the condition all of the time and with better understanding comes better treatments.

What is headshaking in horses? Originally considered a bad habit, headshaking is characterized by the involuntary (and violent) shaking of the head, either up and down or side to side. In 98% of cases, it’s caused by a cranial nerve (known as the trigeminal nerve) continually firing and causing the horse a great deal of pain.

What does it mean when a horseshakes his head?

Horses can shake their head for a number of reasons and in most cases, it’ll be nothing more than the horse trying to get rid of a pesky fly but while the horse may shake their head it’s generally not considered to be a headshaker.

Instead, a true headshaker is said to be a horse that shakes its head (and or rubs its nose) in an uncontrollable manner. The headshaking can be mild and nothing more than a slight irritation (for both the horse and rider), but it can also be so violent and frantic that the horse is not only dangerous to ride but can’t even eat properly. 

Headshaking can make horses dangerous to ride

What are the symptoms of headshaking in horses?

While headshaking is obviously the most common symptom of the condition horses can also show a number of other symptoms, depending on what’s causing them to headshake. Some horses have been known to rub or muzzle their noses on their legs so vigorously that they’ve literally worn the skin away from the legs.

Other symptoms of headshaking include:

  • Head slinging or twisting
  • Wiping nose on the ground
  • Sores on the face
  • Inflamed nostrils
  • Banging head against the stall
  • Hypersensitive to touch
  • Sneezing/snorting
  • Coughing
  • Staring blankly into space
  • Eye tearing or swelling
  • Extreme agitation

What causes headshaking syndrome in horses?

In the past, very little was known about headshaking and it was often considered to be nothing more than a bad habit that should be ignored or corrected but thankfully these days we understand the condition far better.

There’s a vast array of different causes for headshaking in horses but essentially they can all be put into one of two types, those caused by a physical problem (such as pain or behavioral issues), or those that are caused by a firing of the trigeminal nerve (sometimes referred to as trigeminal-mediated headshaking). 

Physical headshaking

Horses that headshake due to pain can be suffering from pain in any part of their bodies but pain around their head (such as those caused by a poorly fitted bridle or bit, or those caused by dental issues) or back are the most common. They can also headshake in response to pain or discomfort caused by an incompetent rider. While nobody likes to admit they have issues with their riding, something as simple as being overly firm with the reins can result in a horse headshaking.

In most cases, pain-associated headshaking can easily be cured by removing the cause of the pain.

While it’s not as common some horses headshake as a way of asserting their dominance or as a way of getting out of doing any work. In these cases reasserting your role as leader will help to correct this behavior.

Trigeminal-mediated headshaking

When it comes to trigeminal-mediated headshaking there are two different types depending on the cause. Photic headshaking (sometimes called photosensitive headshaking), where the horse’s trigeminal nerve is overstimulated by external forces such as light, wind, noise, and even pollen particles, and idiopathic or spontaneous headshaking where there are no external stimuli at all. 

Idiopathic headshaking can often be the most distressing for the horse (and owner) because there is no obvious cause and the horse can suffer to such an extent that they’re not always able to eat.

The trigeminal nerve in horses is the cause of 98% cases of headshaking
The diagram above shows the trigeminal nerve and the path it takes from the brain

How is headshaking diagnosed in horses?

Diagnosing the condition itself is the easy part, after all the violent jolting of the head is very noticeable, the real challenge is determining what the root cause is. 

If you suspect your horse is a chronic headshaker then it’s important to observe them in a variety of different conditions and situations. Are they doing it more when the sun is bright or when the weather is particularly windy or are they only doing it when they’re being ridden? Keeping a detailed record of this behavior will help your vet to make a better diagnosis. It’s also advisable to video the horse headshaking, this might not seem necessary but some horses will stop headshaking on the day of examination so a visual record will help your vet.

In order to determine the underlying cause, some vets may suggest a Bute trial to help with the diagnosis, if the horse shows signs of improvement then the headshaking is caused by some sort of pain or behavioral issue. Whereas, if the horse shows no signs of improvement at all then the vet can be confident in diagnosing trigeminal-mediated headshaking.

As well as a Bute trial, your vet may perform a number of other tests such as detailed examinations of the ears, eyes, and teeth. They may also take blood samples, ear swabs, or run CT or MRI scans.

How common is headshaking in horses?

Most horses will headshake at some point in their lives, this is perfectly normal (and often done as a way of dealing with nuisances such as flies) and nothing to worry about. Chronic headshakers (those that have been doing it for three months or longer), on the other hand, are far less common. All horses can suffer from headshaking, regardless of breed, although it’s more common in Thoroughbreds, Quarter Horses, and Warmbloods.

While there have never been any official studies into how many horses headshake it’s believed that 4.5% of all horses (approximately 2,626,925 horses) will suffer from chronic headshaking at some point in their lives. Out of this, 20% will only do it while at rest with the remaining 80% doing it while being ridden. 

Headshaking affects over 2 million horses

Over 2 million horses might seem like an awful lot but out of those horses roughly only 1% of those will suffer to such an extent that veterinary intervention will be necessary, not that that makes it any easier for those horses or owners. The good news though is that in most cases the headshaking can be managed if not treated completely.

It’s also worth mentioning that while any horse can suffer from headshaking around 63% to 72% of all cases involve geldings, while it’s not known exactly why this is the case it’s believed that the reproductive hormones may inhibit the sensitivity of the trigeminal nerve. 

Natural (or homeopathic) remedies for headshaking in horses

While headshaking can start (and stop) suddenly, for many horses it can last for years and can be difficult to treat with conventional medicine which is why many owners have turned to natural or homeopathic alternatives to mainstream drugs.

Sadly there is no treatment that is 100% successful in 100% of horses 100% of the time, instead, there are a variety of different treatments that will work for some horses. These treatments can also be combined to provide a more effective cure.

Nose nets

Using a mask with a nose net is probably one of the simplest and yet most effective ways of treating trigeminal-mediated headshaking and can offer a great deal of relief to around 25% of horses. It was once believed that the nose net stopped flies or dust particles from entering the horse’s nostrils but it’s recently been discovered that this isn’t quite the case. While the net will obviously prevent foreign bodies from irritating the horse’s airways it’s actually the stimulation the net provides that helps to reduce or even stop the headshaking. Being so close to the sensitive nerves, the net is constantly stimulating it which means that it’s actually suppressing the overactive nerve.

Many companies offer masks with nose nets but I’ve found this one to be the best, it’s lightweight, hard-wearing, and relatively cheap. You can buy them on Amazon.

UV masks

If your horse’s headshaking is caused by an over-sensitivity to bright light then reducing the amount of light that’s hitting his eyes will, in most cases, stop the behavior altogether. While turned out, a mask that offers 90% UV protection will really help to prevent the light from artificially stimulating the nerves.

Some masks also come with ear covers that can help to prevent headshaking in horses that suffer from wind sensitivity. I personally love the Absorbine Ultra Shield and use it on my horses, but if you prefer one with ears then I’d recommend the Harrison Howard CareMaster, not only does it cover the ears but it’s also available in a few colors. Both of which are available on Amazon.

A UV fly mask with a nose covering can really help to stop horses headshaking

Tinted contact lenses

Not all horses are happy wearing a mask while out riding but this can often be when the headshaking is at its worst, especially if you’re riding in and out of the shadows a lot. If your horse doesn’t like masks then tinted contact lenses or UV glasses can help to block out the light while riding.

They’re relatively new on the market but I’ve found a company that will ship them anywhere in the world. And as an added bonus they have a range of different colors. You can buy them directly from the Protective Pet Solutions website.

Changing turnout time

If you notice that your horse’s headshaking is worse when he’s turned out in bright sunlight bringing him in when the sun is at its brightest can have a drastic improvement. This improvement is magnified if you’re able to keep him in a darkened stall during the day and turn him out at night.

Don’t worry if you don’t have a darkened stall, you can cover windows and entrances with UV mesh curtains to help reduce the intensity of the sunlight. Due to their mesh, the air can still flow through into your horse’s stall so don’t worry about the airflow. You don’t need to worry about buying special horse curtains, any will do the job just as well, such as these ones I found on Amazon.

Bug management 

While it’s not as common as was once thought, flies and bugs can cause some horses to headshake. The good news though is that with a bit of simple fly and bug management the problem should subside pretty quickly. Horse-safe fly sprays, fly sheets, and fly traps can all help to reduce the number of flying pests. I’ve included links to fly sheets and traps on Amazon but you can easily make your own fly spray by boiling a sliced lemon in a pint of water for around 10 hours before letting it cool and then siphoning it into spray bottles.

Magnesium

While magnesium won’t always completely cure trigeminal-mediated headshaking it can help to reduce the threshold for the nerves firing which will help to decrease the horse’s hypersensitivity to whatever is triggering the nerve. 

The drawback to magnesium though is that horses can suffer serious side effects if they have too much, this is why you should always speak to your vet before giving your horse magnesium. They’ll be able to give you some guidance on the dosage but will also be able to monitor the amount of magnesium in your horse’s bloodstream.

Check tack

Poorly fitted tack counts for a huge number of headshaking cases (around 1% of all cases, or approximately 26,270 horses) so it’s a good idea to make sure your horse’s tack isn’t causing them any pain. Make sure the saddle is in the right place and not rubbing against your horse’s withers or their back.

You should also make sure the bridle or halter aren’t putting unnecessary pressure on the trigeminal nerve. If they are then investing in a bridle and or halter that has a padding lining can help to dissipate the pressure and therefore reduce the sensation on the nerve.

Check teeth

Horse’s teeth are always growing which is a good thing because as the horse eats they’re also filing their teeth down but this can sometimes lead to the teeth wearing unevenly, causing sharp points and edges. Having an equine dentist or your vet check these (and float them if necessary) will often stop the headshaking overnight.

Wolf teeth in young horses can also, on occasions, interfere with the bit, causing the horse to headshake out of discomfort and sometimes even pain. This is one of the reasons why some owners choose to have their horse’s wolf teeth removed.

PENS

Percutaneous electrical nerve stimulation (or PENS for short) is a promising new treatment, albeit one that does have a considerable cost involved. It has a 6 out of 7 horse success rate and works by using small needles to apply an electric current around the area of the trigeminal nerve.

Like a lot of other treatments, PENS isn’t a permanent cure but it can help to control the headshaking and to make the horse a lot more comfortable. 

Acupuncture

Acupuncture, or electroacupuncture as it’s sometimes called, uses tiny needles to stimulate the sensitive nerves with an electrical impulse. It works in a similar way to PENS but isn’t quite the same thing, acupuncture uses specific points, known as energy lines, around the body whereas PENS stimulates the area specifically around the trigeminal nerve. Acupuncture is also a darn site cheaper than PENS!

A study carried out in 2017 showed that electroacupuncture can help to relieve the symptoms of headshaking in horses 

Equine craniosacral therapy 

While some owners will swear blind that equine craniosacral therapy works there is very limited research to either confirm or contradict those claims which is why I decided to include it here. It’s a holistic therapy that uses light touch to apply pressure to the central nervous system in order to move fluids around in an attempt to free up the horse’s natural bodily flow. This is thought to ‘reset’ the horse’s nerves (as well as remove any restrictions of movement of the head, spine, and pelvis). It’s also believed to relax and calm the horse too.

Homeopathy

Homeopathy is often thought to be a new branch of medicine that’s nothing more than snake oil but this couldn’t be further from the truth, on both counts. Homeopathy, which simply put is the use of natural substances (such as plants and minerals) to treat the body has been around for hundreds of years.

Many owners that do try it report that their horses have made a drastic improvement, although there is no evidence to back this up.

One of the most popular forms of homeopathy is zoopharmacognosy which is based on an animal’s ability to self-medicate by inducing or applying certain plants. I’m not suggesting that horses go out and find the best cure for themselves but instead that practitioners use essential oils derived from these plants to help treat the horse.

How do you treat headshaking in horses?

There’s no miracle cure or quick fix that will stop your horse headshaking once and for all which is why there’s a lot of trial and error. Not all treatment methods work for all horses so most vets will recommend you start with one treatment at first and that you give it long enough to see if it’s effective, sadly though this could be many years in the case of seasonal headshakers.

While many of the natural remedies above do work you may find that your horse responds better to a more conventional, medical form of treatment. This can range from things drugs such as Gabapentin to treat neuropathic pain, antihistamines such as hydroxyzine or cyproheptadine, or even anticonvulsants such as carbamazepine. 

In the most extreme cases, bilateral infraorbital neurectomy (a surgical procedure where a small section of the nerve ending is removed) is an option but this has limited success (only around 16% of horses improve) combined with a chance of serious side effects. Another procedure that has around an 84% success rate is caudal compression of the infraorbital nerve. This uses a platinum coil to compress the infraorbital nerve and horses often see a marked improvement within just 24 hours. [source

Horses can headshake at any time

Related questions

Can you use melatonin for horses that headshake?

Melatonin is a naturally produced hormone that is found in higher amounts when the days get shorter which is why some vets use it to trick the horse’s body into thinking it’s always winter and therefore hopefully preventing seasonal headshaking. 

Can you use a stronger bit to stop a horse headshaking?

There’s a school of thought that says using a harsh or severe bit will stop a horse from headshaking, but this is completely wrong. If anything it’s more likely to cause your horse to do it even more and a stronger bit will cause them more pain and discomfort. Evidence has shown that headshakers actually prefer a milder bit or even a bosal.

Likewise, tiedowns, martingales even side reins don’t work either and they prevent the horse from lifting his head up rather than addressing the real reason why he’s doing it.

Further reading


I hope you found this article helpful. If you did I’d be grateful if you could share it please as it would really help me.

Recommended products 

Over the years I have tried hundreds of different horsey products, from various blankets and halters to different treats. Some I’ve loved, others I’ve hated but I thought I’d share with you my top all-time favorite products, the ones I never leave the yard without. I’ve included links to the products (which are in no particular order) that I really think are great.

  • Mane ’n Tail Detangler – Even if you never show your horse you’ll need to detangle his tail from time to time (and possibly his mane too) which is always a challenging chore! I’ve found that if I run a little bit of detangler through my horse’s tails every few days it stops them from getting matted up and makes combing them easy, even if they’re coated in mud. I don’t know if I should admit to this or not but it also works wonders on my hair.
  • TAKEKIT Pro clippers – Over the years I’ve tried a lot of different clippers and while some were obviously better than others I found these to be by far the best. They are heavier than a lot of other clippers but for me, that’s a good thing, it makes them feel more sturdy and hardwearing. On top of that they have a range of speeds so are just as good for clipping your horse’s back as they are his face. I also like the fact that they come in a handy carry case but that’s not for everybody. The company that makes them is super good and incredibly helpful too, a real bonus these days. The only thing I wasn’t keen on was the fact that it doesn’t come with any oil, but that’s not a major problem as it’s not difficult to buy lubricant.
  • Shire’s ball feeder – There are so many boredom buster toys out there but I like to use these every day, regardless of whether or not my horses are bored. I find that it helps to encourage my horses to problem solve by rewarding them with treats (or pieces of fruit) but it also mimics their natural grazing behavior which helps to keep them calm and de-stressed.
  • Horse safe mirror – This is a strange one that many people are surprised about but I like to put horse safe mirrors in the trailers as well as in the quarantine stalls. It helps to prevent the feeling of isolation by giving the impression of other horses being around. Being herd animals horses can get extremely stressed when they feel that they’re on their own but with these stick-on mirrors, they believe that at least one other horse is with them.
  • Rectal thermometer – I know this isn’t glamourous at all but it’s vital for your horse’s well-being to be able to check their temperature and a rectal thermometer is the easiest way of doing this which is why I’ve added it to the list.

Shopping lists

I’ve also put together a few shopping lists of essential items that I’ve found helpful over the years. I’ve broken the lists down into different categories rather than put everything in one massive list 😉

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