Page 1239 - Problem-Based Feline Medicine

59 – THE CAT WITH OCULAR DISCHARGE OR CHANGED CONJUNCTIVAL APPEARANCE 1231

Diagnosis
ORBITAL DISEASE CAUSING OCULAR
Diagnosis is based on signs of ocular pain with a DISCHARGE AND CHANGED
serous discharge, and the presence a corneal deficit on CONJUNCTIVAL APPEARANCE
examination of the cornea.

The ulcerated area of cornea will retain fluorescein dye RETROBULBAR INFECTION
(staining yellow-green).
Classical signs
CORNEAL SEQUESTRUM** ● Prominent globe (exophthalmos).
● Chemosis of the conjunctiva, with injected
Classical signs blood vessels and a mucopurulent
discharge.
● A serous or mucopurulent ocular
● The third eyelid may be prominent or
discharge.
swollen.
● Brown staining of the cornea.
● Pain and reluctance to open the mouth.
● +/- Signs of ocular discomfort.
● Rare.
See main reference on page 1233 for details (The Cat With
See main reference on page 1310 (The Cat With an
Abnormalities Confined to the Cornea).
Abnormal Globe Position or Size).
Clinical signs
Clinical signs
Corneal sequestrum is more common in brachy-
cephalic breeds such as Persians and color-points, but Cats will have varying degrees of exophthalmos,
can occur in any breed. depending on the extent of the orbital inflammation.

The classical presentation is an area of brown or black In acute cases, there is usually a mucopurulent dis-
staining of the cornea, which may be superficial, or charge, that may be copious if there is orbital cellulitis.
involve deep layers of the stroma. The lesion rarely
The conjunctiva may be red with injected blood ves-
absorbs fluorescein dye, except in cases where the
sels, and show chemosis (edema).
periphery is ulcerated.
The third eyelid is prominent and may be swollen,
A serous ocular discharge is present in non-ulcerated
when the swelling is outside the muscle cone in the
cases.
orbit.
Chronic cases may have ulceration around the dis-
Acute cases show severe pain, and resist opening the
eased area of cornea. These often have secondary bac-
mouth.
terial infection, and a mucopurulent ocular discharge.
It may be difficult to retropulse the globe into the orbit.
Cats may or may not show signs of ocular discomfort.
Retrobulbar infection may be hematogenous, associ-
There may be a history of herpesvirus infection as a
ated with foreign body penetration, or from extension
kitten. However, there are probably other causes, such
of dental or sinus disease. Check the cat for signs of
as medial entropion in brachycephalic cats and corneal
dental disease, especially molar root disease, or nasal
ulceration.
discharge.
Diagnosis It is rare in cats compared to dogs.
Clinical signs of ocular discharge associated with
brown staining of the cornea. Diagnosis
Sequestrum may be associated with FHV-1 infection, Initial diagnosis is based on the classical signs of
which can be confirmed with laboratory tests. exophthalmos, with chemosis and inflammation of the