Page 938 - Problem-Based Feline Medicine

930 PART 11 CAT WITH AN ABNORMAL GAIT

Radiation therapy (45–48 Gy) may control tumor Other systemic signs such as vomiting, coughing and
growth of some brain tumors. diarrhea may be seen concurrently.
Treatment options of tumors of the ear include surgical
resection/debulking, radiation and chemotherapies. Diagnosis

Complete blood cell count may show evidence of sys-
ENCEPHALITIS*** temic inflammation (e.g. leukocytosis).

Classical signs Serum biochemical analysis may show evidence of
systemic abnormalities if the disease diffusely affects
● Diffuse or multifocal neurological signs. the body (e.g. vasculitis) such as elevated globulin, CK,
● Cerebellar signs such as intention tremor, liver enzymes or creatinine.
ataxia, hypermetria, head tilt and nystagmus.
● Cervical pain can be present. Evaluation of titers for the infectious diseases often helps
● Fever is an inconsistent finding. to rule in or rule out the diseases.
● Clues of systemic inflammatory disease ● Infectious agents causing brain disease include
such as chorioretinitis are often present. viral (feline infectious peritonitis), fungal (crypto-
● Other signs of polysystemic disease such coccosis, blastomycosis, histoplasmosis, coccidioido-
as coughing, vomiting or diarrhea may be mycosis, aspergillosis), protozoal (toxoplasmosis,
present. neosporosis), bacterial, rickettsial, and unclassified
organisms (protothecosis).
See main reference on page 859 for details (The Cat ● Involvement of the intracranial nervous system can
With Tremor or Twitching). occur with parasites such as Cuterebra larvae, tox-
ocara and aberrant heartworm migration.

Clinical signs Cerebrospinal fluid analysis (CSF) will usually show
evidence of increased nucleated cells and/or elevated
Depression, inappetence or anorexia and weight loss
protein content. Occasionally, CSF will be normal.
are common.
● Evidence of inflammation on CSF evaluation alone,
Clinical signs often reflect multiple levels of neurolog- however, is not specific for primary encephalitis as
ical involvement. Neurological signs may indicate dif- other CNS disease (e.g. neoplasia) may result in a
fuse or multifocal disease and often do not localize to CSF pleocytosis and protein increases.
a single area within the nervous system. ● With feline infectious peritonitis (FIP), cere-
brospinal fluid analysis may show a pleocytosis,
Paresis, gait abnormalities, proprioceptive deficits,
with either mononuclear or non-lytic neutrophils
cranial nerve defects, depression and occasionally
as the predominant cell type and elevated protein
stupor or coma may occur depending on the areas of
concentration, often > 1 g/L (0.1 g/dl). High serum
brain involved.
coronavirus titers are not diagnostic.
Signs such as intention tremor, cerebellar ataxia (incoor- ● With toxoplasmosis, cerebrospinal fluid frequently
dination and swaying from side to side), hypermetria, contains a pleocytosis, usually with mononuclear
head tilt and nystagmus may occur with involvement of cells, and occasionally, eosinophils. Increasing IgG
the cerebellum. or a single positive IgM serum antibody titer is
suggestive of active infection. Animals with neuro-
Cervical pain can be present.
logic signs and positive IgM titers warrant treat-
Fever is an inconsistent finding. ment for the disease.

Fundic examination is important to look for clues of sys- With cryptococcosis, identification of the organism
temic inflammatory disease as chorioretinitis, which is from cytological evaluation of samples such as CSF,
often present with diseases causing systematic infection. nasal discharge and skin lesions supports the diagnosis.