HEAD SHAKING – separating fact from fiction

Head-shaking – separating fact from fiction

Head-shaking is one of those conditions which, like sweet-itch and the presence of sarcoids, can devalue a horse dramatically, so some owners are reluctant to admit their horse is a head-shaker, whilst others panic at the slightest twitch immediately investing in all sorts of supplements and accessories, to no avail because the horse is not actually a genuine head-shaker.
Firstly all horses and ponies shake their heads, particularly in the summer when biting insects are at their peak, and most animals will shake their heads hundreds of times a day. With this in mind it’s important to understand what distinguishes a head-shaker from a horse that’s simply trying to get rid of an irritant such as a horse fly or a too-tight brow band.

So what is head-shaking?

The condition is now commonly accepted to be caused by an abnormal function of the trigeminal nerve system i.e. the trigeminal nerve transmits the signals that cause the horse to head-shake. It’s believed that the condition is similar to the trigeminal neuralgia suffered by people and if this is the case then the horse would experience at best a burning or tingling and at worse a very sudden and severe pain in the facial area.  Limited post-mortems have shown no damage to the trigeminal nerve, which would account for why some horses seasonally head-shake and would confirm a bio-chemical dysfunction as a cause of head-shaking

This neuropathic pain causes the classic sudden and violent head movements seen in affected horses where there is a downward movement of the head closely followed by a very abrupt upward ‘flick’ of the nose.  The head movement can be coupled with snorting and sometimes striking out movements of a foreleg.  Owners and riders of these horses describe it as if the horse or pony has a “bee in its nose”.  This pain can be constant, intermittent, and also seasonal.  Affected horses will also rub their noses and faces against anything and everything within reach.  Both these symptoms can become pathological and also dangerous for the handler or rider as the horse attempts to alleviate its discomfort.

There is also a type of head-shaker known as “photic” and these animals are ultra-sensitive to bright light, such as sunlight, and also artificial lighting.  Their head-shaking tends to be seasonal and they often seek out shade to relieve their discomfort.

So what can be done for head-shakers?
  • It’s important to understand that with head-shaking symptoms will vary from horse to horse and the intensity or duration of these symptoms can also vary depending on the season or the type of trigger.
  • There are various ways of treating a head-shaker and they include:
  • Physical therapies such as nose nets, acupuncture, and chiropractic treatment, and field studies have tended to show nose nets to be most effective.  With a photic head-shaker an obvious physical therapy would be to keep the horse indoors where practical.
  • Dietary therapies such as weight-loss, as studies have shown that overweight animals are more prone to developing the conditions, and feed supplements. Herbal supplements which include Devils Claw (anti-inflammatory), Eyebright (specific for rhinitis), and Scullcap (specific for hysteria) have shown good results in field trials.  Some studies have shown supplementation with melatonin and also magnesium can have an effect.  Although there are several magnesium supplements on the market great care should be taken not to overdose and blood magnesium levels should be monitored.
  • Drug therapies such as cyproheptadine (particularly for photic head-shakers) and Phenobarbital have been used; however all these therapies carry the risk of side-effects so their use should be carried out under veterinary supervision only.
  • New therapies such as caudal compression of the infraorbital nerve, where a platinum coil is placed into the nerve ends to relieve pain, and Cromoglygate eye drops, which have shown to alleviate symptoms in a significant number of seasonal and photic head-shakers, are worth investigating in conjunction with a veterinary surgeon.
  • Although a head-shaking diagnosis can be a depressing event it’s certainly not the end of the world and research continues to find a universal remedy for the condition.
Some interesting facts:
(courtesy of www.headshakerinfo.org which is an American website) Head-shaking can be seen in any breed. In one study the following breeds were affected:

•Thoroughbred (41%) (three times more likely to be affected than other breeds)
•Quarter horses & Coloureds (24%)
•Warmbloods (16%)
•Other breeds (19%) Morgan, Arabian, Paso Fino, Appaloosa
•Head-shaking can develop at any age (the average age of onset is 9yrs)
•Head-shaking can develop in any sex.  Although 50% to 85% of affected horses are geldings head-shaking occurs in mares and stallions as well 
•64% of head-shakers are affected seasonally
•Geldings are more likely than mares to be seasonally affected
•Seasonal head-shaking tends to be significantly worse on sunny days but improves on rainy days, windy days, at night and indoors. (however, some individuals are made worse by the wind)
•50% of head-shakers only show symptoms during exercise

•Horses who are overweight are over-represented (are more likely to develop head-shaking)
•Having a period when the horse is out of work may contribute to onset of head-shaking
•Some horses in ‘remission’ can be stimulated out of this remission by an electric shock, such as from an electric fence
•Some horses do outgrow head-shaking. After head-shaking for several years, they stop.  This may occur in as many as 20-30% of cases based on some observations

Reference sources used to compile this article:
Science Daily http://www.sciencedaily.com/releases/2012/11/121114113721.htm
Horse & Hound
The Horse magazine
Bristol University

Article supplied by Hilton Herbs
Supplements, Lotions, & Creams for Horses & Ponies
A range of products which are 100% natural, and formulated by a fully qualified Medical Herbalist, and manufactured in the UK with full UFAS traceability from human-grade herbs. www.hiltonherbs.com
Hilton Herbs logo