Page 628 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Respir atory system: 3.2 Surgical conditions of the respir atory tr act 603

VetBooks.ir Antibiotic and/or antiseptic treatments should be 3.15
withdrawn if possible.
Antifungal solutions used include enilconazole,
miconazole, ketoconazole and natamycin. The use
of nystatin powder can also be useful where lesions
are difficult to lavage with solutions. Some clinicians
use systemic iodides as an additional treatment, but
these are rarely necessary.

Prognosis
The prognosis is very good. Recurrence or persis-
tence of lesions is rare and is a sign that the fungal
infection is a result of an underlying disease that
requires additional treatment. Limiting the use of Fig. 3.15 The same lesion as in Fig. 3.14 48 h after
antibiotics helps to prevent the development of this dislodging the mycotic plaque and irrigating the area
disease. with enilconazole.

PARANASAL SINUSES

PRIMARY SINUSITIS (increasingly purulent). A mixed bacterial growth
is often isolated. With chronicity, empyema and
Definition/overview inspissation of the exudate can occur. In primary
This is a frequent condition, particularly of animals sinusitis of the rostral maxillary and ventral conchal
with a history of URT disease. The anatomy of the sinuses, the drainage is even more restricted and
paranasal sinus compartments is very complex. From once empyema is established successful drainage is
a clinical standpoint the sinus compartments can be much harder to achieve. With increasing exudate
divided into two: the rostral maxillary/ventral con- there may be expansion of the conchal walls of the
chal (lateral and medial to the teeth and infraorbital paranasal sinuses and increasing obstruction of the
canal) and all the others (Fig. 3.16a–c). The other airway.
sinus compartments include the frontal, concho-
frontal and caudal maxillary. All of the latter com- Clinical presentation
municate with each other through large openings Primary sinusitis invariably presents with a unilat-
and drain via a single slit-like opening in the cau- eral mucopurulent or purulent nasal discharge, often
dal middle meatus of the nasal passages. The rostral copious in quantity and, in chronic cases, increas-
maxillary sinus has its own separate drainage ostia in ingly malodourous (Fig. 3.17). Bilateral cases are
the middle meatus. rare. The discharge may increase after exercise or
feeding from the ground. There is often a unilateral
Aetiology/pathophysiology lymphadenopathy of the submandibular lymph node
A URT infection leads to increased mucus produc- on the affected side. Less frequently, conchal swell-
tion and compromised mucociliary clearance, with ing leads to nasal distortion, resulting in reduced air-
stagnation of the mucus in the dependent sinuses. flow, an abnormal respiratory noise and occasionally
The relatively small and poorly sited drainage ostia exercise intolerance. External facial swelling may also
are further compromised by surrounding mucosal occlude the nasolacrimal duct, resulting in epiphora
inflammation, which with chronicity can become and/or ocular discharge (Fig. 3.17). The facial swell-
hyperplastic. Secondary bacterial infection is com- ing is located over the paranasal sinuses caudal to the
mon, further increasing the production of fluid rostral edge of the facial crest (Fig. 3.18).