What You Need to Know about Horse Headshaking Syndrome

Start by knowing what Headshaking Syndrome is. So what is a head shaker?

Equine Headshaking Syndrome is Trigeminal-Mediated Headshaking. It is caused by the trigeminal nerve misfiring and sending shock sensations to the horse’s head. This condition is called photic headshaking and is caused by strong sunlight.

Next, understand how to identify a horse with this condition. So how is the photic head shaker spotted?

Identifying Horses with Headshaking Syndrome

It is a reaction to sunlight, so horses are frequently affected in the Spring and Summer, but some have symptoms all year round. The condition can be extreme or less problematic. In bad cases, a horse will display the following signs:

• Seeking shade where possible
• Constant nose or face rubbing against objects
• Frequent sneezing and snorting
• Uncontrollable head shaking
• In the most severe cases, the horse will act as if it has a bee up its nose and will be agitated and dangerous to the point of striking out at its face with its legs and stamp the ground.

How the Headshaking Appears

The headshaking takes on different forms and these are:

• A head tick and/or quivering of the upper lip, with or without any of the signs below
• Throwing the head up, which is the most common type of shaking
• Throwing the head side to side
• Rotating the head back and forth as if a fly is being a nuisance around the ears
• Violently rotating the neck and head to one side often accompanied by throwing the head up
• In some cases, there is no head tick or lip quiver.

When to expect a Headshaking Incident

For different horses, there are different triggers and although sunlight is the primary cause episodes can be induced by:

• Strong winds
• Pollen
• Dust
• Being ridden
• Other things.

There may be Other Reasons for Headshaking that are not Trigeminal-Mediated Headshaking

Lots of things can cause headshaking so it is prudent to rule out other causes and this will need veterinary assistance.

Riding a Head Shaker

Some horses head shake while ridden. Others continually shake and in extreme cases will need to be euthanised for humane reasons.

The horse with exercise-induced headshaking may need to be retired. This will depend on the intensity and vigour of the shake.

Some Head Shakers are Symptom Free in Autumn and Winter

The seasonal head shaker could be ridden for half of the year. Many good field hunters in the UK have been seasonal head shakers.

Headshaking Syndrome is Incurable

The condition affects horses at any age and develops quickly. Typically the middle age horse is more likely to develop the syndrome with roughly twice as many geldings as mares being affected. About 2% of the horse population has Trigeminal-Mediated Headshaking, but at present, little effective medical treatment is available.

Managing the Condition

For some horses nose nets and face masks reduce or stop head shaking. Follow these suggestions about using nose/face masks and also feed the additive mentioned:

• Try a nose net that comes right down the nose and just round the upper lip
• If this does not work go to a full face mask with an ultraviolet screen and if the nose section does not come down to the upper lip also use a nose net that does
• Feed a magnesium food supplement in case your horse has a deficiency
• Adding salt to a horse’s diet can have a positive effect.

The nose net applies slight pressure on the nose and with some horses, this is enough to stop the trigeminal nerve from misfiring. The full face mask with a UV filter will reduce the amount of light on the horse’s eyes and with some horses, this helps to reduce or stops the symptoms of headshaking. Finally, feeding a magnesium supplement and additional salt helps horses with magnesium-deficient impaired nerve function and so this might help reduce the symptoms.

If the above does not help the only remaining option is to seek veterinary help.

Going to Veterinary Support

Headshaking Syndrome is not fully understood and at present veterinary science does not provide a permanent solution. Diagnostic testing is through observing the clinical signs rather than identifying a structural disease.

Response to treatments is variable with at best a low success rate. However, electrical nerve stimulation (PENS) is now being used and the data suggests improvement or remission in 39% of cases for a moderate period of time.