Page 439 - Problem-Based Feline Medicine

21 – THE YELLOW CAT OR CAT WITH ELEVATED LIVER ENZYMES 431

Increased activities of ALT and ALP are common. – Give human interferon-β 30 IU/day for 7 days at
Total bilirubin values may be increased above 2–3 alternate weeks to boost immunity.
mg/dl (jaundice). – Nutritional support via force feedings,
esophagostomy or gastrostomy tube, or naso-
Diagnostic sampling of effusions is useful as they are
esophageal catheter.
generally high protein but low to moderate cellularity
● Because of the extremely poor prognosis, euthana-
(modified transudate) with non-lytic neutrophils.
sia is recommended if there is no response to pal-
Serologic testing for FIP antibodies may give con- liative therapy.
founding results. Coronaviral antibodies are wide-
spread in the general cat population and the new 7B FIP
antibody test appears to have problems with false neg- LYMPHOSARCOMA*
atives and false positives in the field.
● Reverse transcriptase-PCR detection of coronaviral Classical signs
antigens in effusion fluid or tissues presently lacks
● Most cats > 10 years of age.
high diagnostic accuracy. False positives occur
● Lethargy, anorexia, weight loss.
because enteric coronavirus may be present system-
● Jaundice may be present.
ically, and false-negative results also occur.
● Hepatomegaly +/- effusion (ascites or
● Immunocytochemistry demonstrating coronavirus
hemoperitoneum).
antigen within circulating monocytes or tissue
macrophages appears to be specific, but low num-
bers of infected cells in tissue samples limit the sen-
sitivity for use in biopsy samples. The technique is Pathogenesis
only available at some laboratories.
Generally presents as a manifestation of multicentric
lymphosarcoma. Lesions may occur in conjunction
Differential diagnosis with neoplastic infiltrates involving other lymphoid
organs, such as peripheral lymph nodes, or the alimen-
Abdominocentesis in FIP-infected cats may yield a
tary mucosa.
protein-rich exudate which is dissimilar from other
inflammatory/degenerative hepatopathies except lym- Neoplastic lymphocytes gradually replace normal
phocytic cholangiohepatitis. Histopathology of the hepatocytes causing organ enlargement and hepatic
liver is diagnostic. Also, differentiate FIP from car- failure.
diomyopathy and neoplasia which may cause chronic ● Cholestasis and jaundice result from involvement of
illness similar to FIP or cavity effusion. intrahepatic biliary structures.

Cats with FIP will often have involvement of multiple
organ systems (eyes, lungs, CNS). Clinical signs
Mostly seen in middle-aged and older cats.
Treatment
Lethargy, anorexia, and weight loss predominate.
There is no definitive therapy for FIP and the disease is
Hepatomegaly +/− jaundice are common.
almost uniformly fatal in cats with signs.
● Supportive care is palliative at best.
– Immunosuppressive doses of steroids (2–4 mg/kg Diagnosis
PO q 24 h) +/− other cytotoxic drugs (e.g.,
Suspicion of hepatic neoplasia is raised by older age,
cyclophosphamide 2.2 mg/kg/day on four consec-
history of chronic illness and suggestive clinical signs.
utive days each week or chlorambucil 20 mg/m 2
every 2–3 weeks) are recommended for vasculitis. Increased serum ALT and ALP activities are common.
– Administer broad-spectrum antimicrobials for In general, relatively greater increases in ALT versus
secondary bacterial infections. ALP are observed.