Page 282 - Problem-Based Feline Medicine

274 PART 5 CAT WITH ACUTE ILLNESS

should also be considered in any critically ill cat devel- – Elevated fTLI is not specific for pancreatitis.
oping pleural effusion, ascites or hypothermia. Elevations may also be seen in inflammatory
bowel disease, intestinal lymphoma and renal
Laboratory findings are variable and are most valu-
failure.
able in ruling out other causes of depression and
– fTLI is not as widely available as other laboratory
anorexia.
tests, and delays in reporting reduce its utility.
Hematology abnormalities include: ● The measurement of trypsinogen activation peptide
● Mild non-regenerative anemia. may be useful in the future.
● Neutrophilia, with or without a left shift (inflam- ● Feline pancreatic lipase immunoreactivity (fPLI)
matory leukogram). appears to be a very sensitive test for acute pancre-
● Neutropenia. atitis, but is currently not widely available.
● Lymphopenia (stress leukogram). ● Abdominal fluid is usually a modified transudate
● Thrombocytopenia (consumption). but may be a non-septic exudate. Pleural fluid is
usually a modified transudate.
Serum biochemistry abnormalities include eleva-
tions in liver enzymes (with a tendency to be higher in Diagnostic imaging findings are also variable.
chronic pancreatitis), bilirubin, cholesterol, urea and
Abdominal radiography is most useful in ruling out
creatinine, and decreases in potassium, calcium and
other causes of vomiting.
albumin. Lower concentrations of ionized calcium
● Radiographic findings are often normal and do not
have been associated with a poor prognosis in acute
rule out pancreatitis.
pancreatitis. Low serum cobalamin levels may be
● If abnormalities are present, they are similar to
present.
those of acute pancreatitis in dogs: decreased
Blood glucose concentration may be increased, normal cranial abdominal contrast (due to effusion), a
or low. Mild coagulation abnormalities may be present. mass effect (displacement of organs) in the right
● Serum amylase and lipase levels are infrequently cranial quadrant due to the swollen pancreas), and
elevated in naturally occurring pancreatitis (poor localized dilation of loops of intestine (due to
sensitivity). ileus).
– Serum amylase levels may be elevated by dehy-
Abdominal ultrasonography is more useful than radi-
dration, and amylase and lipase levels may be
ography. Ideally high-resolution equipment should be
elevated by renal failure. An elevated lipase
used. (Abdominal ultrasonography, fTLI and fPLI are
level in the presence of normal renal function is
the best non-invasive tests for pancreatitis.)
probably highly specific for pancreatitis.
● Normal findings do not rule out pancreatitis
– There may be a greater likelihood of detecting
(reported sensitivity is 11–80%).
an elevated lipase level if measured immediately
● Abnormalities with a high specificity for pancre-
after the onset of clinical signs.
atitis include pancreatic regular or irregular
– In one model of experimental pancreatitis, amy-
enlargement, pancreatic hypoechogenicity, hypere-
lase levels actually decreased from baseline val-
chogenicity of peripancreatic fat (may be difficult
ues during the first week of illness.
to appreciate), dilation of the pancreatic duct in the
– Decreased lipase level usually rules out pancre-
left lobe and accumulation of peritoneal fluid
atitis in the dog; it is not known if this is also true
around the pancreas. Less specific changes include
for the cat.
dilated common bile duct and gall bladder, cranial
– The utility of measuring amylase and lipase in
abdominal mass effect, generalized peritoneal effu-
peritoneal effusion has not been evaluated in
sion and mesenteric lymphadenopathy. If a
clinical cases.
pancreatic mass is identified, it is most likely a neo-
● A more useful laboratory test is feline trypsin-like
plasm, followed by a pseudocyst. Pancreatic abscesses
immunoreactivity (fTLI).
are rare. Hepatic parenchymal and gastrointestinal
– fTLI is a more sensitive test than amylase or
changes may also be present because of associated
lipase for pancreatitis, but a normal value does
conditions.
not rule out pancreatitis.