Head Shakers

Headshaking , Photic head tossers, allergic rhinitis.

The above terms are often used to describe horses that particularly during the hotter dryer and lighter months of the year are often seen tossing their heads in the air for no apparent reason. The more severe may self mutilate by striking at the nostrils with their fore feet. Others may be seen cantering through a field with their nostrils brushing through the grass.

Most theories as to the reason why this occurs centre around changes to the nervous system. Increases in neural sensitivity particularly to ‘light’ (reaching the ocular retina -eye) and also to ‘touch’ (in the nasal mucosas) are more commonly reported.  The trigeminal nerve or a trigeminal neuritis may be the centre of these problems .

Treatments are often aimed at either avoiding stimuli by

  (i) reducing the amount of light entering the eyes (sunglasses/lenses)  

  (ii) only working horse in colder darker months of the year.

  (iii) avoiding light and dusty environments.

  or by using neural blocking agents . Several medications have proven to be useful at managing this condition.

It has also been noted that in many instances these horses appear to very sensitive or hyperaesthetic about the 2nd and 3rd cervicospinal joints in the neck. Reduction in this sensitivity following under anaesthetic mobilisation of the cervical spine has resulted in a significant reduction in symptoms in the greater percentage of cases treated in this manner. Some were treated twice at intervals of 8-12 weeks. In one case where symptoms were recent ( first season) a complete return to normal behaviour was observed.

Reference ;-

Cervical vertebral mobilisation under anaesthetic (CVMUA) a physical therapy for the treatment of cervicospinal pain and stiffness.

J of Equine Vet Sci  1994 ; 14: 540-545.