Changes

Dorsal displacement of the soft palate is a '''performance-limiting condition''' of the upper respiratory tract and is a relatively common cause of upper respiratory noise during exercise.

Dorsal displacement of the soft palate is a '''performance-limiting condition''' of the upper respiratory tract and is a relatively common cause of upper respiratory noise during exercise.

During DDSP, the '''caudal free margin of the soft palate moves dorsal to the epiglottis''', creating a functional obstruction within the airway.

During DDSP, the '''caudal free margin of the [[Soft Palate|soft palate]] moves dorsal to the [[Larynx - Anatomy & Physiology#Epiglottis|epiglottis]]''', creating a functional obstruction within the airway.

DDSP can be persistent or, more commonly, intermittent.

DDSP can be persistent or, more commonly, intermittent.

Horses with '''persistent disease''' present with severe exercise intolerance and respiratory noise. There may be concurrent epiglottic entrapment or neurological deficits.

Horses with '''persistent disease''' present with severe exercise intolerance and respiratory noise. There may be concurrent [[Epiglottic Entrapment|epiglottic entrapment]] or neurological deficits.

'''Intermittent DDSP''' arises as an acute respiratory obstruction that occurs '''during fast exercise'''. The condition can occur secondary to other conditions, and may be a symptom rather than a disease in its own right.

'''Intermittent DDSP''' arises as an acute respiratory obstruction that occurs '''during fast exercise'''. The condition can occur secondary to other conditions, and may be a symptom rather than a disease in its own right.

Underlying causes include:

Underlying causes include:

:'''Conditions causing fatigue''': unthriftiness, primary cardiovascular disorders, primary pulmonary diseases like small airway inflammation, recurrent laryngeal neuropathy

:'''Conditions causing fatigue''': unthriftiness, primary cardiovascular disorders, primary pulmonary diseases like small airway inflammation, [[Laryngeal Hemiplegia|recurrent laryngeal neuropathy]]

:'''Disorders of the palate''': congenital or iatrogenic defects, ulceration of the free border, intrapalatal cysts, pharyngeal paralysis

:'''Disorders of the palate''': congenital or iatrogenic defects, ulceration of the free border, intrapalatal cysts, pharyngeal paralysis

:'''Disorders of the epiglottis''': hypoplasia, deformity, [[Epiglottic Entrapment|entrapment]], subepiglottic cysts, epiglottitis

:'''Disorders of the epiglottis''': hypoplasia, deformity, [[Epiglottic Entrapment|entrapment]], subepiglottic cysts, epiglottitis

:'''Conditions causing mouth breathing''': neglected dental disease, retained caps, harsh bit

:'''Conditions causing mouth breathing''': neglected dental disease, retained caps, harsh bit

:'''Conditions provoking pharyngeal discomfort''': pharyngeal lymphoid hyperplasia, pharyngitis, pharyngeal cysts, upper respiratory tract infections, neoplasia

:'''Conditions provoking pharyngeal discomfort''': [[Pharyngeal Lymphoid Hyperplasia|pharyngeal lymphoid hyperplasia]], [[pharyngitis]], pharyngeal cysts, upper respiratory tract infections, neoplasia

:'''Neuromuscular dysfunction''': extrinsic or intrinsic muscles controlling soft palate position

:'''Neuromuscular dysfunction''': extrinsic or intrinsic muscles controlling soft palate position dysfunction

==Clinical Signs==

==Clinical Signs==

Intermittent DDSP occurs during exercise. It causes a '''loud vibrant noise''', described as 'gurgling' and an interference with the progress of the horse: 'choking up' or 'choking down'. The horse often loses its stride completely as it gulps and attempts to restore the larynx to the intranarial position. As soon as the normal anatomical configuration is restored, the horse will '''appear normal''' and it can resume galloping.

Intermittent DDSP occurs during exercise. It causes a '''loud vibrant noise''', described as 'gurgling' and an interference with the progress of the horse, 'choking up' or 'choking down'. The horse often loses its stride completely as it gulps and attempts to restore the larynx to the intranarial position. As soon as the normal anatomical configuration is restored, the horse will '''appear normal''' and it can resume galloping.

DDSP usually occurs when the horse reaches the '''point of maximal exertion''', usually in the later stages of a race.

DDSP usually occurs when the horse reaches the '''point of maximal exertion''', usually in the later stages of a race.

'''Endoscopic examination''' at rest may enable a diagnosis to be made, however as the condition is intermittent the horse may appear normal.

'''Endoscopic examination''' at rest may enable a diagnosis to be made, however as the condition is intermittent the horse may appear normal.

The gold standard is an '''exercising endoscopic examination''' using a treadmill.

The gold standard is an '''exercising endoscopic examination''' using a treadmill or remote endoscopy is now also available.

'''Tracheal washings samples''' can be taken and examined by cytology and culture to find any underlying inflammation or infection.

'''Tracheal washings samples''' can be taken and examined by cytology and culture to find any underlying inflammation or infection.

{{Learning

{{Learning

|flashcards = [[Equine Internal Medicine Q&A 07]]

|flashcards = [[Nasopharynx_Flashcards_-_Pathology|Nasopharynx Pathology Flashcards]]<br>[[Equine Internal Medicine Q&A 07]]

}}

}}

Merck and Co (2008) '''The Merck Veterinary Manual''' ''Merial''

Merck and Co (2008) '''The Merck Veterinary Manual''' ''Merial''

[[Category:Nasopharynx - Pathology]]

[[Category:Nasopharynx - Pathology]]

[[Category:Respiratory System - Degenerative Pathology]]

[[Category:Respiratory System - Degenerative Pathology]]