Page 329 - Problem-Based Feline Medicine

17 – THE CAT WITH WEIGHT LOSS AND A GOOD APPETITE 321

● The only condition that may be associated with mon bile duct obstruction. Associated findings may
polyphagia is lymphocytic cholangitis/cholangio- include enlarged mesenteric lymph nodes, pancreatic
hepatitis. irregularity, and/or thickening of the duodenal walls.
Pathogenesis of lymphocytic cholangitis/cholangio- A definitive diagnosis is made by histopathological
hepatitis complex is unknown. It is probably immune- examination of a liver biopsy.
mediated, but is possibly associated with progression of ● A fine-needle aspirate is rarely diagnostic, so a per-
the suppurative form. It is often associated with IBD cutaneous needle biopsy or surgical wedge
and/or pancreatitis, and when all three occur biopsy is required. Blood clotting times and/or a
together it is termed “triaditis”. PIVKA test (protein induced by vitamin K absence
or antagonism) should be assessed first, and a
platelet count should be performed.
Clinical signs
● Typical gross findings include a very firm often
Cats of any age may be affected, but disease is seen rather irregular liver, and a thickened and dis-
most typically in middle-aged cats. Persian cats may tended gallbladder and common bile duct, which
have an increased risk. often contains inspissated bile. Enlarged mesenteric
lymph nodes, pancreatic irregularity and/or thick-
Clinical signs are usually chronic and insidious in
ening of the duodenal walls may also be present.
nature.
● If performing an exploratory laparotomy, it is sensi-
Affected cats are typically jaundiced, but bright, and ble to check the patency of the biliary outflow, then
are often polyphagic. collect biopsies from the mesenteric lymph nodes,
small intestines and pancreas as well as liver. Send
Vomiting and/or diarrhea may be present.
bile and part of the liver biopsy for culture.
Cats may have a palpably enlarged liver and mild ● Histopathology of the liver reveals lymphocytic
generalized lymphadenopathy. and/or plasmacytic periportal inflammation,
bile ductule hyperplasia, and periportal fibrosis.
Cats may show intermittent signs of systemic illness,
Very chronic cases may have biliary cirrhosis.
with fever, anorexia, weight loss, and vomiting.
Systemic signs are sometimes associated with second-
ary infections, typically of the liver and/or pancreas.
Differential diagnosis
The disease may progress to causing chronic biliary cir-
These include most of the other causes of weight loss
rhosis with ascites, hepatic encephalopathy, and bleed-
with a good appetite. However, since cats with lympho-
ing tendencies.
cytic cholangitis/cholangiohepatitis complex often
develop vomiting and/or diarrhea enteropathies (includ-
Diagnosis ing IBD), pancreatitis, and the other malassimilation
syndromes should be considered as important differen-
Serum biochemistry often reveals mild to moderately
tials. In cases that develop ascites, the wet form of feline
(occasionally severely) increased liver enzymes,
infectious peritonitis (FIP) should also be considered.
increased bile acids, hyperbilirubinemia, hyperglobu-
This is because both conditions produce a protein-rich
linemia and hypoalbuminemia.
ascitic fluid and have similar biochemical and hemato-
Hematology may reveal mild anemia, lymphopenia or logical changes. However, the presence of polyphagia
lymphocytosis, monocytosis and/or thrombocytopenia. usually differentiates the two conditions as cats with FIP
Blood clotting times are frequently prolonged. are usually anorexic.
Ascitic fluid, if present, is typically high in protein.

Radiographs typically reveal hepatomegaly and occa- Treatment
sionally choleliths (gallstones), while ultrasound
Treatment is largely empirical.
examination may also show blotchy hepatic hypere-
chogenicity, “sludging” of bile, and evidence of com- Antibiotics, if needed: