Page 1274 - Problem-Based Feline Medicine

1266 PART 15 CAT WITH EYE PROBLEMS

Cats with ocular signs of FIP rarely show systemic
FELINE INFECTIOUS PERITONITIS
signs of illness such as fever, inappetence and weight
loss at the initial presentation. As the disease
Classical signs
becomes chronic, weight loss and neurological signs
● Young cats 6–12 months of age. develop.
● Anterior uveitis with large fibrin clots
(hypopyon).
● Large brownish to pink keratic precipitates Diagnosis
on the inferior endothelial surface of the
cornea. There is no definitive diagnosis for FIP.
● Chorioretinitis causing variable vision loss A tentative diagnosis is initially based on clinical signs;
and/or abnormal pupil reflexes. a young cat with uveitis showing hypopyon and ker-
● Neurological signs, including behavioral atic precipitates.
changes, cranial nerve abnormalities,
seizures and head tremor. Serology is usually regarded as being of dubious bene-
fit in the diagnosis, as the FIP organism cross-reacts
with enteric forms of coronavirus.
See the main reference on page 1179 (The Blind Cat or
Cat With Retinal Disease). Diagnosis can only be confirmed on characteristic
histopathology of affected tissues on biopsy or
necropsy examination. The typical change is described
Clinical signs as a pyogranulomatous vasculitis. Necrosis and a
fibrinoid response are seen in some cases. The ocular
The ocular form of the disease is usually seen in young
cellular response includes neutrophils, lymphocytes,
cats from 6 months to 1 year of age.
plasma cells, macrophages and large, spindle-shaped
Ocular signs may be unilateral or bilateral. histiocytes.
The main presenting sign is uveitis. Large fibrin Cats often have a large increase in plasma total pro-
clots mixed with exudated white and red blood cells tein, globulin and IgG concentration, because of the
form a hypopyon. Keratic precipitates are common chronic nature of the inflammatory disease process.
and appear as large pinkish, brown spots on the inferior The polyclonal increase in gammaglobulins is caused
endothelial surface of the cornea (“mutton fat by virus antigen and cell destruction from the intense
deposits”). inflammation associated with the infection.

The vitreous may be hazy due to a similar exudation of
cells from the ciliary body.
FELINE LEUKEMIA VIRUS*
The retina may show a focal or total exudative retinal
detachment. It is common to see an inflammatory exu-
Classical signs
date sheathing the major retinal blood vessels, which
form a cloudy sheath around the vessels. ● Discrete iris or ciliary body masses (FeLV-
associated lymphosarcoma).
Blindness may be seen with abnormal pupil reflexes
● Anterior uveitis.
(miotic in early stages with uveitis, followed by dilation
● Intermittent asymmetric changes in pupil
in blind cases) and abnormal pupil size (anisocoria).
size, shape or response.
Cats with ocular signs frequently develop neurological ● Other FeLV-associated signs, e.g. anemia.
signs, and die or are euthanized as a result of menin- ● Retinal detachment.
gioencephalitis and its associated signs, which include
behavioral changes, cranial nerve abnormalities, seizures See the main reference on page 1300 (The Cat With
and head tremor (seizures most common). Abnormal Iris Appearance).