Page 1331 - Problem-Based Feline Medicine

65 – THE CAT WITH ABNORMAL EYELID APPEARANCE 1323

Diagnosis Classical signs—Cont’d

Tentative diagnosis is based on appearance of the ● Trichiasis with secondary keratitis and
skin lesions, and the clinical history of exposure to corneal vascularization.
other cats with similar lesions or a suspected carrier cat.

Some organisms (Microsporum canis) demonstrate flu- Pathogenesis
orescence under UV light. Negative findings under
UV light examination should not be used to rule out There is an abnormality in development and differenti-
dermatophyte infection. “False” fluorescence of epider- ation of surface ectoderm and possibly neural crest
mal scales can sometimes be interpreted as a positive mesenchyme.
result. Breed predisposition may occur, as the disease appears
Definitive diagnosis is made by microscopic exami- to be seen more commonly in Persian kittens.
nation of hair shafts and by culture of the organ-
ism. Microscopic examination may reveal the Clinical signs
presence of small ectothrix, or endothrix spores on or
in the keratin at the base of the hair shaft. Microsporum Often seen as a bilateral abnormality, usually of the
canis is the most common cause. Microsporum gyp- upper lateral eyelid. There is gradual transition
seum is identified less commonly, while Trichophyton from haired skin to conjunctiva, with absence of a
species are rarely implicated in feline dermatophyte normal lid margin.
infections. Corneal disease occurs because of trichiasis (hair
rubbing on the cornea) associated with the absence of
Differential diagnosis a normal margin, which results in corneal ulceration
and vascularization.
Autoimmune skin disease can be ruled out by histo-
pathological examination of affected skin.
Diagnosis

Treatment Diagnosis is based on the characteristic appearance of
the deficient eyelid margin in a young cat, with sec-
Many different treatments are recommended in the lit- ondary keratitis caused by irritation of the trichiasis.
erature but more common ones include:
● Griseofulvin 12.5 mg/kg PO q 12 h for 4–6 weeks.
Drug should be given with a fatty meal to enhance Treatment
absorption. The drug is teratogenic if given to preg-
Surgical techniques are aimed at removing the ab-
nant queens.
normal area of eyelid and joining normal lid margins
● Ketoconazole 10 mg/kg PO q 24 h.
together. The method depends on the size and position
● Topical treatments containing compounds such as
of the defect.
miconazole or povidine iodine are also effective.
Some other compounds such as chlorine may be If the eyelid defect is small, a V-shaped wedge of the
irritant when used around the eye. abnormal eyelid may be resected and the normal lid
sutured together using a figure-of-eight suture to
appose the margins.
EYELID AGENESIS/EYELID COLOBOMA*
If there are larger, lateral upper lid defects, the lower
Classical signs lid margin at the lateral canthus may be joined to the
medial aspect of the upper lid defect, making a new lat-
● Absence of normal eyelid margin, with
eral canthus.
transition from haired skin to conjunctiva.
● Often bilateral, usually involving lateral Larger defects involve surgical correction by trans-
upper lids in a young cat. position of a strip of skin and associated orbicularis mus-
cle from the lower eyelid to the upper defect. The