Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

Clinical Examination of the Head and Neck
Roof of pharynx
Left arytenoid
cartilage
Epiglottis
Figure 5.16 Bovine larynx viewed
through a wide tube passed through the
mouth.
The endoscope
In adult cattle a 1 metre long endoscope 11 mm in
diameter can usually be passed along the ventral
meatus of the nasal cavity. In smaller animals a
human paediatric endoscope may be needed.
Introduction of the endoscope
Local gel anaesthetic is applied topically to both nostrils.
The objective end of the endoscope is introduced
quickly past the sensitive nasal mucosa. It is
inserted as medially and as ventrally as possible into
the ventral meatus. Once within the nasal cavity
it appears to cause little discomfort. An assistant
passes the endoscope slowly forward as the operator
views the visible structures.
Nasal cavity The mucosa of the ventral meatus and
the ventral turbinate bone is pink in colour. It may be
thickened and inflamed in cases of upper respiratory
infection. The endoscope may occasionally impinge
on and be obstructed by the ethmoid bone in the
caudal part of the nasal passage. If the endoscope is
withdrawn slightly and redirected ventrally to the
ethmoid bone it can usually be passed towards the
pharynx without difficulty. At other times vision
may be obscured by the end of the endoscope making
contact with the mucosa at any point during the
examination. Slight withdrawal of the endoscope
and flushing its end will usually allow its position
and surroundings to be ascertained.
Pharynx This appears to be longer and less spacious
than that of the horse. Swallowing movements
by the patient further reduce the apparent size of the
pharynx. The mobile soft palate forms the ventral
floor of the nasopharynx and the two small openings
of the Eustachian tubes are visible in the dorsolateral
walls of the pharynx. Occasionally, signs of traumatic
injury may be seen in the pharyngeal walls.
The roof of the pharynx may be depressed by enlarged
and infected retropharyngeal lymph nodes.
Larynx This may not be visible until the endoscope
has passed well into the pharynx. The two arytenoid
cartilages are very large in cattle and extend dorsally
over the laryngeal aditus partially obscuring it (Fig.
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