Page 440 - Problem-Based Feline Medicine

432 PART 7 SICK CAT WITH SPECIFIC SIGNS

Radiographic imaging may aid diagnosis. Clinical signs
● Symmetrical hepatomegaly is often observed on
Infection with the obligate intracellular coccidia causes
survey radiographs.
inflammation and cell necrosis in affected tissues.
● Hepatic sonography shows generalized hyper-
Lung, brain, gut, liver and eye are most affected.
echogenicity or multifocal hypoechogenicity to the
liver parenchyma. Diverse but are generally referable to respiratory, neu-
romuscular or gastrointestinal systems.
Definitive diagnosis requires cytologic or histologic
evaluation of liver specimens. Anorexia, cyclical fever, dyspnea and lethargy are
common.
Differential diagnosis Uveitis may involve one or both eyes.
Rule out benign conditions, such as hepatic cysts, hepa- Cystic involvement of the CNS may cause pronounced
tocellular/bile duct adenomas, and regenerative nodules neurologic deficits (with the type of observed CNS
which may mimic hepatic lymphosarcoma. These other deficit dependent upon involvement of the brain, brain
diseases may be definitively ruled out by performance stem and/or spinal cord), or may be rapidly fatal with
of liver biopsy with histologic interpretation. advanced disease.

Cysts located within skeletal muscles are painful, and
Treatment often cause hyperesthesia on muscle palpation, stiff-
ness of gait and shifting leg lameness.
Combination chemotherapy using cyclophosphamide
2
2
(300 mg/m PO q 3 weeks), vincristine (0.75 mg/m IV Hepatic involvement may follow dissemination causing
weekly for 4 weeks), and prednisone (2 mg/kg/day) is jaundice due to hepatitis or cholangiohepatitis. Cystic
recommended. See page 676 for treatment details. involvement of the intestinal mucosa may cause lympho-
cytic-plasmacytic enteritis.
Provide supportive therapy (including provision of
enteral feeding if needed) as needed.
Diagnosis
Prognosis
Non-regenerative anemia and leukopenia.
The prognosis is guarded. Approximately 50% of cats
Marked increases in serum ALT and AST activities
with hepatic lymphosarcoma will respond to multi-
occur with hepatic infection.
drug chemotherapy.
Hyperproteinemia occurs in some cats with chronic
Concurrent FeLV infection shortens survival times but
toxoplasmosis.
does not influence response to chemotherapy.
Thoracic radiographs may demonstrate diffuse intersti-
tial to alveolar opacities.
TOXOPLASMOSIS* Serologic testing provides useful diagnostic information.
● IgM and IgG titers are assessed by ELISA tech-
Classical signs niques.
– A high (> 256) IgM titer is suggestive of active
● Anorexia, lethargy, neurologic signs and
infection.
dyspnea.
–A 4 × rise in IgG titer over 2–3 weeks is sugges-
● Cyclical fever.
tive of active infection.
● +/- icterus, vomiting and diarrhea.
● Anterior or posterior uveitis. Demonstration of the organism (cysts) in affected
biopsy/necropsy tissues is helpful in making a
See main reference, page 375 (The Pyrexic Cat). diagnosis.