Page 936 - Problem-Based Feline Medicine

928 PART 11 CAT WITH AN ABNORMAL GAIT

This virus destroys the external germinal layer of the Differential diagnosis
cerebellum and prevents the formation of the granular
In this age of cat, other inflammatory central nervous
layer.
system abnormalities such as toxoplasmosis infection
Some affected cats have a concurrent hydrocephalus are possible.
and hydranencephaly.
Congenital anatomical defects of the cerebellum may
cause similar signs.
Clinical signs
Trauma occurring at a young age may permanently
Clinical signs are present from the early prenatal period damage the cerebellum producing similar signs.
but are most apparent when the animal begins purpose-
ful movement and attempts to walk.
Treatment
Tremor accompanying the disease usually has a slow
No treatment is currently helpful for cats affected with
frequency (2–6 times/second) and large amplitude
this disease.
(course tremor). The tremor worsens (increases in fre-
quency or amplitude), when the cat moves in a goal-
oriented way (e.g. bends down to eat), which is termed Prognosis
an intention tremor.
Clinical signs associated with previous panleukopenia
Other signs include ataxia (incoordination; swaying virus infection of the developing cerebellum usually
from side to side), hypermetria (“goose-stepping”; remain static or improve with growth, causing the
overflexing of the limbs when walking), menace tremor to become less apparent.
deficits (with normal vision and pupillary light
reflexes), head tilt and nystagmus (combination quick
Prevention
followed by slow movement of the eyes).
Do not vaccinate queens with modified live pan-
Clinical signs usually remain static or improve with
leukopenia virus vaccine.
growth as the cat compensates, causing the tremor to
become less apparent.
CEREBELLAR OR VESTIBULAR TUMOR***

Diagnosis Classical signs
Antemortem testing for panleukopenia often results in ● Signs usually begin in cats 5 years of age
negative findings. or older.
● Signs usually are progressive over weeks
Routine laboratory investigations are normal.
to months.
Definitive diagnosis is usually only obtained at ● Occasionally, clinical signs begin acutely.
necropsy and histopathological examination of the ● Intention tremor is often associated with
nervous tissue. other signs of cerebellar disease including
ataxia, dysmetria, menace deficits, head tilt
In some instances of cerebellar atrophy, a smaller than
and nystagmus.
normal cerebellum may be seen on magnetic reso-
nance imaging of the intracranial nervous system. This
See main reference on page 821 for details (The Cat
is most readily seen on the sagittal view.
With Stupor or Coma).
Occasionally, inflammatory cells may be present in cere-
brospinal fluid examination in cats with active pan-
Clinical signs
leukopenia viral infection. Cerebrospinal fluid with the
other degenerative cerebellar conditions and with previ- Clinical signs usually begin in cats 5 years of age or
ous panleukopenia infection is usually normal. older.