Page 1099 - Small Animal Clinical Nutrition 5th Edition

1144 Small Animal Clinical Nutrition

polydipsia/polyuria and weight loss (Steiner and Williams, signs. Additionally, these tests may aid in the diagnosis of con-
VetBooks.ir 1997). In others, hepatic lipidosis or cholangiohepatitis may oc- current medical conditions such as diabetes mellitus, hepatic
lipidosis, interstitial nephritis and cholangiohepatitis.
cur concurrently resulting in icterus (Akol et al, 1993; Weiss et
Anorectic or vomiting canine and feline patients with pancre-
al, 1996). In some cats, pancreatitis, cholangiohepatitis and in-
flammatory bowel disease (IBD) may be present simultaneous- atitis may become hypokalemic. In one retrospective study, hy-
ly (triaditis). pocalcemia was recognized in 40% of cats with acute pancreati-
Depression, fever and dehydration may be the most promi- tis and was considered indicative of a poor prognosis (Kimmel
nent physical examination findings. Abdominal palpation may et al, 2001). Hypocalcemia may be attributable to conditions
elicit splinting and discomfort that can be localized to the right such as hypoalbuminemia, parathormone resistance or to the
cranial quadrant. Icterus, shock and coagulopathies may be de- saponification of calcium by fatty acids (Kimmel et al, 2001;
tected in severe cases. Washabau, 2001).
Clinical manifestations are variable in chronic pancreatitis. An inflammatory leukogram is typically identified in patients
Weight loss and poor body condition may be the only signs with pancreatitis. A degenerative left shift may indicate severe
noted in cats. An abnormal thickening or hardness of the falci- necrotic pancreatitis. In cats, leukopenia appears to occur more
form fat pad may be palpated in some cats, suggesting saponi- commonly than in dogs and is associated with a poor progno-
fication and fat necrosis. sis (Washabau, 2001). If thrombocytopenia is noted on the he-
mogram, a complete coagulation screen should be performed to
Laboratory and Other Clinical Information rule out disseminated intravascular coagulation.
The laboratory diagnosis of acute and chronic pancreatitis can Imaging can be useful for diagnosing pancreatitis in dogs
be very frustrating. Diagnosis is hampered by the poor speci- and cats. Findings consistent with pancreatic inflammation
ficity of available laboratory tests and the inaccessibility of tis- on survey abdominal radiographs may include haziness and
sue for cytologic or histopathologic examination. Serum amy- widening of the gastroduodenal angle in the right cranial
lase and lipase activities are the most commonly used laborato- quadrant. Often, segmental gas distention of the proximal
ry tests for the diagnosis of pancreatitis in dogs and cats. duodenum is noted. In the hands of an experienced operator,
Unfortunately, these tests are not very specific because they are abdominal ultrasonography appears to be a sensitive test for
influenced by a number of other disease conditions (e.g., renal the diagnosis of acute pancreatitis in dogs (Mansfield et al,
failure, dehydration, hyperlipidemia). In addition, the short 2008). Typical findings include enlargement of the pancreas,
half-life of amylase and lipase often precludes their use as diag- hypoechogenicity, dilatation of the pancreatic duct and hyper-
nostic aids unless the patient is presented promptly after the echogenicity of the mesentery. Peripancreatic fluid accumula-
onset of clinical signs. If present, hyperamylasemia and hyper- tion is a common finding in dogs and cats (Williams, 2006).
lipasemia support a diagnosis of pancreatitis if azotemia and Ultrasonography may reveal fluid-filled cysts, pseudocysts or
hyperlipidemia are not present. In cats, pancreatic amylase abscesses within the pancreatic parenchyma and can be used
secretion is only 10% of that in dogs and serum amylase is usu- to guide needle aspiration of pancreatic masses (Salisbury et
ally low in cats with pancreatitis (Zoran, 2007). al, 1988; VanEnkevort et al, 1999). In cats, the reported sen-
Serum trypsin-like immunoreactivity (TLI) concentration sitivity of abdominal ultrasonography ranges from 20 to 67%
has been suggested as a diagnostic aid for evaluating dogs and (Rademacher et al, 2008). Typical ultrasonographic findings
cats with suspected pancreatitis. Because TLI is specifically in cats are similar to those described in dogs. More sophisti-
pancreatic in origin, high serum TLI concentrations were cated contrast-enhanced power and color Doppler ultrasono-
hoped to be a more reliable indicator of clinical pancreatitis graphic procedures also distinguish between normal cats and
than high amylase or lipase activities (Simpson et al, 1989). cats with pancreatitis (Rademacher et al, 2008). When cou-
However, the sensitivity of TLI assays in dogs and cats with pled with measurement of serum pancreatic lipase immunore-
acute pancreatitis appears to be very low (30 to 60%) activity, abdominal ultrasonography was more sensitive than
(Williams, 2006). computed tomography in the diagnosis of acute pancreatitis
More recently, assays for canine and feline specific pancreat- in cats (Forman et al, 2004).
ic lipase have come into clinical use. In healthy dogs and cats, The gold standard for diagnosing acute and chronic pan-
very little pancreatic lipase is present in blood. In pancreatitis, creatitis is histopathology. Unfortunately, pancreatic biopsies
the inflamed organ leaks larger amounts of lipase into the are rarely performed because of the invasive nature of the pro-
blood, which is measurable by immunoassay. These species- cedure and because many patients with pancreatitis are poor
specific assays appear to be more sensitive (>80%) than TLI anesthetic risks. However, laparoscopic techniques for the di-
concentrations for the diagnosis of pancreatitis in dogs and cats agnosis of pancreatic disease in dogs and cats have been de-
(Steiner, 2006; Forman et al, 2002). Additionally, these assays scribed; these provide a minimally invasive method for collec-
are not falsely elevated in renal disease (Steiner et al, 2001) or tion of pancreatic biopsy specimens (Marmoinen et al, 2002;
by corticosteroid administration (Steiner et al, 2003). Webb and Trott, 2008). Unfortunately, laparoscopy does not
A complete blood cell count, serum biochemistry profile and provide good visualization of the entire pancreas, which can
urinalysis should be done for any dog or cat suspected to have result in failure to biopsy affected areas of the organ (Steiner,
pancreatitis to rule out other potential causes for the clinical 2008).