Page 1342 - Problem-Based Feline Medicine

1334 PART 15 CAT WITH EYE PROBLEMS

Differential diagnosis Differential diagnosis

Infectious conjunctivitis is usually distinctive and dif- Horner’s syndrome results in acute onset of unilateral
ferentiation between the infectious agents needs to be prominence of the third eyelid whereas Haws is bilateral.
made. The chronic forms of infection may appear sim- Horner’s syndrome is associated with other signs such
ilar to eosinophilic keratoconjunctivitis, which can be as ptosis and a miotic pupil.
differentiated based on cytological examination of deep
scrapings or on histopathology.
Treatment
No treatment is necessary. All cases will resolve with
Treatment
time.
See The Cat With Ocular Discharge or Changed Con-
junctival Appearance (page 1207) for more details.
SQUAMOUS CELL CARCINOMA***
Herpesvirus: topical trifluorothymidine, Idoxuridine,
Vidarabine, topical or oral Acyclovir, topical or oral alpha Classical signs
interferon, oral lysine.
● Verrucous, raised mass usually arising
Chlamydophila felis: topical tetracycline, oral doxycy- from non-pigmented conjunctival surface.
cline, oral azithromycin. ● Erosion and mucopurulent discharge.
Mycoplasma: topical tetracycline or chloramphenicol.
Clinical signs

Pink, proliferative mass with a cauliflower-like
THIRD EYELID DYSAUTONOMIA (verrucous) or ulcerated surface usually arising from
(“HAWS”)*** the non-pigmented conjunctival surface of the third
eyelid. Typically the lesion is associated with erosion,
Classical signs loss of normal tissue architecture and mucopurulent
discharge.
● Bilateral non-painful third eyelid
prominence.
● Usually acute onset, and often resolves Diagnosis
rapidly without treatment within days to
Initial diagnosis is based on the appearance of the
weeks.
lesion.
● Unassociated with other signs of
sympathetic denervation. Cytology and/or histopathology are required for a
definitive diagnosis. Typical cytological appearance
includes large clumps of eosinophilic keratinized
Clinical signs
epithelial cells, and sometimes loss of normal architec-
Bilateral, non-painful third eyelid prominence, usu- ture is visible in the form of whorls or keratin “pearls”.
ally acute in onset and resolves rapidly within days to
weeks. Not associated with other signs of sympathetic Differential diagnosis
denervation such as ptosis and a miotic pupil.
Eosinophilic keratitis is an uncommon proliferative
Sometimes seen in association with acute gastrointesti-
disease of the third eyelid. It may also be associated
nal signs, e.g. diarrhea. One report in the literature found
with corneal disease and cytology is characteristically
an association with torovirus infection.
in the form of eosinophilic infiltrates.
Other neoplastic disease. Hemangiomas are not as
Diagnosis
common, have a smoother surface, and appear as a
Diagnosis is usually based solely on the clinical signs. darker red to purple-colored mass.