Page 518 - The Veterinary Care of the Horse

Causes

At present, we do not know what causes the nerve to become hypersensitive. People with
VetBooks.ir trigeminal neuralgia suffer from unpleasant tingling and burning sensations, or shooting

electric shock-like facial pain, but these are associated with pathological changes within the
nerve that have not been found in horses.

There are a number of known triggers for headshaking, which include:

• bright sunlight
• increased air turbulence and blood flow in the nasal cavities during exercise

• pollen causing nasal irritation

• dust (the nasal mucosa is exposed to increased levels of pollen and dust when the air flow
increases with exercise)

• wind

• cold air

• touch

• warmth
• humidity

• tight nosebands

• applying a twitch

• dental problems
• excitement or stress

• trimming the horse’s whiskers

• fly imitation

Diagnosis

The diagnosis is made by observing the horse at rest and at exercise and ruling out other
possible causes. Take some video for your vet to watch if your horse only headshakes whilst

out on a hack. The headshaking can vary from day to day so video footage is always helpful.
It is important to rule out other possible causes of headshaking, which include:

• discomfort from poorly fitted tack, inappropriate bitting or bad riding

• dental issues, e.g. sharp teeth ulcerating the gums, wolf teeth or tush problems, tooth
infection, diastema (gaps between the teeth where food may collect and irritate the gums)

• neck or back pain