Page 714 - The Veterinary Care of the Horse

Using the bit to ask for excessive neck flexion, e.g. in dressage horses, can cause a
• mechanical displacement of the soft palate and obstruct the airway.

VetBooks.ir Where no specific reason can be found, it may be that during severe exertion the larynx is

pulled backwards and waves of movement in the soft palate allow it to slip upwards from

under the epiglottis and block the airway. Alternatively there may be an abnormality in the
functioning of the nerves and muscles of the soft palate.

Diagnosis

This is usually made from the history and endoscopy whilst the horse is galloping. It can be
performed with the horse on a high-speed treadmill but this requires a period of time for the

horse to become familiar with the procedure. The development of the dynamic overground
video endoscope, which is fitted to the bridle, allows the soft palate to be observed whilst the
horse is working on the gallops.

A routine endoscopic examination with the horse at rest is essential to detect other

abnormalities of the respiratory system which could predispose to DDSP.

Treatment

The first step is to make sure that the horse is fit enough for the work being asked of it.

Sometimes the condition goes away as the horse reaches peak fitness. Other horses grow out
of the condition with no treatment.

The next step is to treat any medical problems that may predispose to DDSP, e.g. lung
disease, pharyngeal inflammation and epiglottic cysts.

TACK CHANGES

The following may be used to stop the horse opening its mouth and to prevent the tongue or
larynx moving backwards.

• A drop, flash or grackle noseband can be used to prevent the horse opening its mouth.

This discourages swallowing.
• An Australian noseband holds the bit high in the mouth and reduces the likelihood of the

horse getting his tongue over the bit which increases the risk of DDSP.
• Tongue straps are used to tie the tongue down into the interdental space and hold them

forward in the mouth. These are considered to be effective and are permitted on the
racecourse. They should be fitted just before the race and removed immediately