Page 1296 - Problem-Based Feline Medicine

1288 PART 15 CAT WITH EYE PROBLEMS

Clinical signs Other signs of severe anemia, e.g. pale mucous mem-
branes, increased respiratory rate and lethargy. Anemia
Cat is older than 10 years of age.
must be profound for this syndrome to occur, i.e. usu-
There is loss of normal coloration because of loss of ally the PCV is less than 10% or hemoglobin less than
pigment in the anterior iris stroma. This may be espe- 5 g/dl.
cially obvious in old Siamese or other color-dilute cats
with blue irides (e.g. Himalayan). The iris can become Diagnosis
so thin, that it may take on a transparent appearance.
Vision is normal. Diagnosis is based initially on the clinical signs of a
severely anemic cat with poor papillary light reflexes
Loss of normal pupillary light reflex is associated with
and multiple small retinal hemorrhages.
atrophy of the pupillary sphincter. This sign is less com-
monly seen in the cat than in the dog, as the pupillary Diagnosis is confirmed on hematology. The cause of
sphincter shape is more often conserved in feline iris the anemia should be identified. Common causes of
atrophy, resulting in a sluggish pupillary light reflex profound anemia include FeLV-associated anemia or
rather than a dilated non-responsive pupil. Visible defects Mycoplasma haemofelis infection. FeLV-associated ane-
may occur around the pupil margin with atrophy. mia may also be accompanied by thrombocytopenia
which may contribute to the retinal hemorrhages.
Diagnosis
HYPERVISCOSITY RETINOPATHY
Diagnosis is based purely on consideration of the age
and breed of the cat, that is, an old color-dilute cat
Classical signs
greater than 10 years of age, and on the clinical signs
of a sluggish pupillary light reflex, and loss of iris ● Blindness and loss of pupil reflexes.
pigmentation. ● Extremely dilated tortuous retinal vessels,
retinal hemorrhages, retinal detachment,
perivascular effusion, optic disc edema.
Treatment
● Monoclonal globulin spike on protein
No treatment is possible for iris atrophy. electrophoresis.

ANEMIC RETINOPATHY
Clinical signs
Classical signs Blindness and loss of pupil reflexes occur due to reti-
nal damage.
● Blind, weak cat with profound anemia.
● Retinal hemorrhages and attenuated, pale Extremely dilated, tortuous retinal vessels, retinal
retinal vessels. hemorrhages, retinal detachment, perivascular effusion
● Partial to complete loss of pupil light and optic disc edema are evident on fundoscopy.
reflex.
A variety of other clinical signs including lethargy,
weight loss, inappetence, pale mucous membranes,
See main reference on page 1186 (The Blind Cat or The
neurological signs and lameness may be exhibited.
Cat With Retinal Disease).
Rare condition in cats.
Clinical signs
Blind cat with partial to complete loss of pupil light Diagnosis
reflex.
Diagnosis is initially based on the suspicious signs seen
Retinal hemorrhages and attenuated, pale retinal on fundoscopy, especially the presence of bizarre,
vessels. dilated, tortuous retinal vessels.