Headshaking


 

 Symptoms and Solutions

 

 

An example of a nose guard to help ameliorate the symptoms of headshaking

This condition is characterised by the shaking of the head up and down or side to side acting as though an insect has gone up the nose.

Headshaking is primarily a disruption or sensitization of the trigeminal nerve.

The objectives of treatment for headshaking

  • is to raise the threshold for the firing of the trigeminal nerve (ie damping down the electrochemical processes that activate the nerve) then the problem is reduced to be manageable and /or eliminated.
  • To improve the integrity of mucus membranes and capillaries surrounding the trigeminal nerve. ie treating nasal lesions, addressing any fluctuations in blood flow through the nasal area.
  • To address stress levels and the adrenal response.
  • To modify any environmental, nutritional or physiological triggers.

Causes:

These may include:

  • Middle ear disorders, ear mites, fungal rhinitis, periodic opthalmia
  • Stress, intense exercise, heat and sunlight seem to make head shaking worse.
  • Head shaking may be the result of a pathophysiologic mechanism in response to light stimulation. Similar to a light-stimulated sneeze in humans.
  • These stimuli affect the sensory branches of the trigeminal nerve in the muzzle area which may explain nasal rubbing, snorting and nose flicking.
  • Alterations in blood flow in nasal area could explain some of this behaviour.
  •  Horses that have been exposed to EHV-1 may be more at risk. Theory behind this is that the herpes virus lies dormant in the trigeminal nerve then with heat, exercise, stress and/or sunlight, becomes active.
  • A disruption to gonadotropin levels. Luteinsing hormone may be higher than should be.

Clinical signs:

  • Flicking of the nose. Rubbing nose on objects
  • Ears stuck out at right angles to the head.
  • Horse will actively seek shady areas
  • Symptoms may worsen in summer and improve with nightfall.

Immediate Action

Have the horse examined by a vet to check for photosensitivity and/or an abnormal build up of seratonin.  Test for any infections. Check teeth and fitting of the bit.

Veterinary Treatment may include:

  • Ant-seratonergic  and antihistamine drugs.
  • Anti-inflammatory drugs.

 

Alternative Preventative and Herbal Treatment.

  • Provide environmental protection from sunlight. Plant shade trees.
  • Look at changing the pasture. Contact us directly for the horse pasture blend.
  • Provide additional Magnesium which will raise the threshold for the firing of the trigeminal nerve. (ie damp down the electrochemical processes that activate the nerve)
  • Provide detox plant material.
  • Reduce inflammation by taking a range of Omega 3 fatty acid  (ALA and GLAs)  . These cold pressed only oils will correct the balance between Prostaglandin E1 and Prostaglandin E2.
  • Omega oils  will help reduce the over-production of noradrenalin which can promote irritability, hostility and excess seratonin.
  • Omega Oil oils may assist in protecting the nerve sheath.
  • Plant material rich in antioxidants and flavonoids will address free radical damage.  Green tea tailings daily, proflavonals from grapeseed, rosehips and Seabuckthorne may help.
  • Restore integrity of blood vessels using some of the following herbs: hawthorn, yarrow, chestnut.
  • To improve blood flow using circulatory herbs like ginkgo and/or white willow bark.
  • Ear mites may be controlled using aromatic oil drops applied to the ears twice daily.
  • The herb valerian will help relax the horse as well as acting as a vasodilator which will prevent fluctuations of  blood flow to muzzle area.
  • Camomile flowers may help with symptoms by being slightly sedating, analgesic and anti-inflammatory
  • A blend of anti seratonic herbs, vasodilators, anti-inflammatories like Devil’s Claw may help with symptoms.
  • Some horses have obtained temporary relief after having ointment containing St John’s Wort and Calendula applied up the nostril.( Note St John’s Wort acts directly on the nerves.
  • Some people have placed a panty hose leg over the muzzle to prevent pollen entering nasal passages which has in some cases given considerable relief.
  • Ointments containing Melissa Officinalis have been effective in treating humans with a similar condition.

DISCLAIMER: The information in this page must not be used in place of professional veterinary treatment . We recommend that either a qualified herbalist or your animal professional carry out diagnosis and subsequent treatment. Herbal remedies must not be given not be taken in conjunction with other medication with out consulting a medical professional.

 Article “NATURAL HORSE MANAGEMENT” October 2015

 

 Headshaking in Horses 

A wonderful example of a Spanish nose guard for headshaking

 

 

There are few conditions that engender more fear and foreboding than headshaking syndrome. To make matters worse these are often accompanied by stories of failure to reduce the horse’s discomfort.

This may be partly because this condition seems to be fraught with conflicting information.

Things can be done to alleviate and ameliorate headshaking but it takes a multi-facetted approach to achieve favourable outcomes.

To this end we need to understand the causes and exact symptoms before confidently providing a course of action.  It also pays to be vigilant, not only in personal observations but record keeping, paying attention to any changes in the environment, feed, saddle or bridle fitting and in particular seasonal changes.

Underlying causes and symptoms need to be diagnosed by a vet and tested at a reputable laboratory before any treatment should be undertaken. Only then can a systematic program be embarked on.

 

What are the Possible Causes and Triggers?

Causes can be endogenous arising internally (physiologically) or exogenous arising externally (usually environmental triggers).

One of the causative endogenous factors that get the most attention is the trigeminal nerve. Now you would expect to see some damage to the nerve at post mortems of head shakers but these have demonstrated that their trigeminal nerves are normal. This is a comforting sign implying that the physiological state of the nerve may return back to normal.

 

So endogenous causes may include:

  • Those horses exposed to EHV-1 may be more at risk. The theory behind this is that the herpes virus lies dormant in the trigeminal nerve.  Then with heat, exercise, stress and/or sunlight, becomes active.
  • Lesions, possibly arising from EHV, that exist in the nasal passage can disrupt normal nerve function caused by fluctuations in blood flow particularly during exercise.
  • A weakened physiology either through stress or systemic inflammation may make the horse more prone to headshaking.
  • It is thought that a reduction in the threshold of perception of the nerve triggers a disproportionate response. The horse perceives this as pain and becomes increasingly distressed and difficult to calm down.
  • Most cases have an abrupt onset called ‘acute onset’.  This may be the first time the specific nerve endings have been stimulated or damage to the nerve has become sufficient to be triggered.
  • The result of a patho-physiologic mechanism in response to light stimulation. Similar to a light-stimulated sneeze in humans.
  • Sensitivity to light may be due to elevated serotonin levels.
  • Alterations in blood flow in nasal area affect the sensory branches of the trigeminal nerve in the muzzle area which may explain nasal rubbing, snorting

 

 

Exogenous causes:

These are determined by the horse’s predisposition to environmental factors ie allergies and hypersensitivity to stimuli.

 

  • Those horses sensitive to light stimulation will get worse in bright sunlight.
  • Stress, intense exercise, heat and sunlight seem to make head shaking worse in some.
  • Seasonal headshaking tends to be significantly worse on sunny days but improving on overcast, rainy, windy days, at night and indoors. (however, some individuals are made worse by the wind)
  • Seasonal headshaking can be variable ie some start in autumn and stop in spring, while most start in the spring and stop in the autumn. This pattern is repeated each year in the same horses almost down to the same calendar week.
  • Normal physiological seasonal events ie horses shed in the springtime and autumn all determined by day length changes.  Studies on seasonal ACTH and adrenal feedback loops indicate that they vary different times of the year to include changes in reproductive hormone levels. Evidence shows that 64% of head shakers are affected seasonally
  • 50% of head shakers only show symptoms during exercise indicating blood flow fluctuations as triggers

What are the clinical signs and symptoms?

The signs of headshaking are loosely categorised into reflex responses to include:

  • Up/down involuntary twitching of the head — movement range varies from mild to severe to include twitching, plus ear and eyelid flicks.
  • Pain responses — rubbing, sweating and rearing or striking at the face. Face rubbing is a common sign that corresponds to areas of perceived pain or numbness, probably linked to damaged parts of the nerve.
  • High or low head carriage.
  • Snorting or high-blowing, sometimes coupled with nasal discharges and behavioural seeking of muzzle protection (under the tail of another horse, a water bucket, etc). This is more symptomatic of an allergic response.
  • Nostril clamping after exercise may suggest the trigger zone is inside the nasal cavity where normal nostril dilation would lead to pain and discomfort.
  • Distracted behaviour may be seen, such as loss of stride, stopping, rearing and striking at the face during exercise at all paces.
  • True headshaking signs are shown in different circumstances, such as free exercise or lungeing, and with different riders.
  • In some cases the clinical and physiological causes have been resolved but what remains is a behavioural by-product that then presents as an evasion.

 

 

Treatment Options:

The conventional outlook for confirmed head shakers is not promising but there are a range of things that can be tried.

 

These three categories are;

1 Veterinary Drug treatments

2 Physical treatments

3. Supplemental and herbal treatments

 

1  Veterinary Drugs

As with any condition characterised by pain and suffering we strongly urge that veterinary diagnosis and treatment is investigated and carried out BEFORE attempting to self medicate your horse. Here are some drugs that may be used by your vet.

Neuropathic drugs are used as an aid to controlling the nerve pain associated with headshaking, while anti-convulsants address involuntary reflex responses movements. Anti-serotonic drugs may be used to calm photic responses and anti-histamines to control allergic reactions.

 

2  Physical Treatments

These methods may be tried at home and you can use them in combination with any of the other treatments (dietary and drug).

  • If light is a trigger: keep the horse indoors during the day. Consider having the horse wear a UV blocking sun shade fly mask. Try a tinted polo eye guard. This is important if serotonin is the trigger, as sunlight (not direct) on the retina stimulates serotonin production.
  • If exercise is a trigger: Use a nose net or other device which attaches to or dangles over the nostril and muzzle area. Some have found a cut-off piece of panty hose to be effective. Ear covering and forehead ‘dangling’ material may help with allergic responses to midges and pollens.

2. Supplemental and Herbal treatments

Herbs and supplements have been helpful in some cases. It is helpful for us to know what drugs the horse may have been recommended because often there are herbal equivalents, in particular anti-serotonic, analgesic and anti-histamine herbs. Here are some suggestions:

  • Magnesium: magnesium is an electrolyte critically involved in nerve function.  Supplementing the diet with ionised magnesium may help decrease the stimulation of the trigeminal nerve. In some cases it is advised to monitor blood magnesium and calcium ratios.
  • Anti-serotonic herbs can be added to herbal blends to help modulate excess serotonin levels. Administering these require a careful assessment of the horse and/or a vet’s diagnosis to verify that the horse exhibits true sun sensitivity.
  • St John’s Wort oil (not the extract to be taken internally) may be applied topically into the horse’s nostril. The active ingredients will migrate into the upper part of the nostrils.  This is useful when there has been nerve damage and nodules and lesions present. This oil is not only an anti-inflammatory but also acts on nerve endings. It is historically recognised as a remedy for the pain associated with shingles.
  • Valerian in combination with the topical St John’s Wort oil will help address the blood flow fluctuation that irritates the nasal tissues flanking the trigeminal nerve by acting as a mild vasodilator. Valerian also acts as an anti-spasmodic to address excessive reflex responses.
  • Chamomile which is a mild anti-histamine, used in conjunction with omega oils, may help with seasonal allergies. Administering vitamin C along with these two will help calm the allergic response.
  • Devil’s Claw may be used as a mild anti-inflammatory. Particularly for those horses that clamp their nostrils.
  • Lemon Balm which is calming has a mild ant-viral action and may help prevent further flare-ups.
  • Melatonin: is produced naturally in the body as darkness falls. Melatonin supplements help trick your horse’s body into thinking it is a different time of year (alteration in photoperiod) and is useful for some seasonal headshakers). This not only resets the horse’s internal seasonal clock (biorhythm) by switching their photoperiod back to winter but will help modulate serotonin production throughout the 24 hour cycle. It must be given every day at 5:00 PM to correlate with the naturally occurring rise of melatonin with onset of darkness throughout the whole year for best results.
  • Spirulina has recentlybeen added to the list of protocols for this condition. Spirulina has biologically available magnesium, amino acids and essential fatty acids that have a mild anti-inflammatory response.  It is claimed to help decrease stimulation of the trigeminal nerve.
  • Maintaining a healthy weight for your horse is of particular importance, as overweight horses may have underlying endocrine problems that will exacerbate the problem.

 

DISCLAIMER: The information in this page must not be used in place of professional veterinary treatment . We recommend that either a qualified herbalist or your animal professional carry out diagnosis and subsequent treatment. Herbal remedies must not be given not be taken in conjunction with other medication with out consulting a medical professional.

Further information which is regularly updated can be found on their web page www.hiralabs.co.nz

 

 


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