Basic HTML Version
SPRING 2013 ISSUE
EQUINE MATTERS
12
RESP I RATORY NOI SE
Condition:
High blowing
Type of noise:
snorting type noise
Presentation:
noise heard on exercise
with no effect on performance
Causes:
vibration of the fold of the
`false nostril
Treatment:
treatment is not normally
necessary
Timing of noise:
expiration
Condition:
Nasal obstruction
Type of noise:
variable, snoring, snorting
Presentation:
noise may be heard at
rest and worsen during exercise or may
only be heard during exercise. Other signs
such as nasal discharge and facial
swelling may be present.
Causes:
sinus infections, cysts, nasal
polyps, tumours
Treatment:
surgery to remove or treat
the obstruction
Timing of noise:
expiration and inspiration
Condition:
Laryngeal hemiplegia
(roaring)
Type of noise:
sharp noise (roar,
gasp, whistle)
Presentation:
noise during fast work
and poor performance in race and
sports horses.
Causes:
partial or total paralysis of one
(most commonly the left) or both of the
arytenoid cartilages of the larynx due
abnormal function of the nerve supplying
the area. Most common in larger horses.
Other causes include nerve trauma and
liver disease.
Treatment:
surgery to the larynx
involving a 'Tie back' procedure to hold
in the arytenoid cartilage in a partially
open position and 'Hobday' procedure
which removes the saccule of the larynx.
Timing of noise:
inspiration
Condition:
Dorsal displacement
of the soft palate
(gurgling)
Type of noise:
gurgle, choking
Presentation:
gurgling or choking noise
and very sudden loss of performance
during a race or fast work
Causes:
the horse's soft palate displaces
up over the epiglottis and blocks the
passage of air.
Treatment/Management:
depending
on severity of the condition, the following
methods may be used to attempt to
prevent the soft palate displacing: use
of a tongue tie or dropped noseband,
soft palate cautery or laser surgery,
laryngeal tie forward surgery.
Timing of noise:
during intense work
(requires an overland scope to diagnose).
What causes noise?
With each breath air is taken in via the
nostrils, through the nasal passages and into
the throat (pharynx). From here it passes
through the larynx, before entering the
trachea and lungs. To allow the horse to take
in more air during exercise, the nostrils dilate
and the horse extends its head and neck, thus
enabling the pharynx and larynx to open
wider and to take in more air. Anything
which interferes with the smooth passage of
air flowing from the nostrils to the lungs may
result in the horse making an audible noise.
There are many other less common causes of upper airway obstruction which
can result in an abnormal respiratory noise. If you are concerned that your horse
may be making an abnormal respiratory noise speak to your local XLVets Equine
practice for more information.
Figure 2.
An endoscopic examination of the
upper airway at rest
Figure 3.
The larynx viewed through an
endoscope during examination
Figure 4. Horse exercising with overland scope in position