Evaluation of serum feline trypsin-like immunoreactivity for the diagnosis of pancreatitis in cats.

To evaluate serum feline trypsin-like immunoreactivity (fTLI) concentration and results of abdominal ultrasonography, CBC, and serum biochemical analyses for diagnosis of pancreatitis in cats. Prospective study. 28 cats with clinical signs compatible with pancreatitis. Serum fTLI concentrations were determined, and abdominal ultrasonography, CBC, and serum biochemical analyses were performed prior to histologic evaluation of pancreatic, hepatic, and intestinal specimens. On the basis of histologic results, cats were categorized as having a normal pancreas (n = 10), pancreatic fibrosis with ongoing inflammation (9), pancreatic fibrosis without inflammation (4), and acute necrotizing pancreatitis (5). Serum fTLI concentrations and results of CBC, serum biochemical analyses, and histologic evaluation of hepatic and intestinal specimens were compared among groups. Significant differences in serum fTLI concentrations or any hematologic or biochemical variable were not detected among the 4 groups of cats. Median serum fTLI concentrations were 51 micrograms/L (range, 18 to 200 micrograms/L) in cats with a normal pancreas, 32 micrograms/L (range, 12 to > 200 micrograms/L) in cats with pancreatic fibrosis and ongoing inflammation, 124 micrograms/L (range, 36 to > 200 micrograms/L) in cats with pancreatic fibrosis without ongoing inflammation, and 30 micrograms/L (range, 24 to 84 micrograms/L) in cats with acute necrotizing pancreatitis. We detected a high prevalence of concurrent hepatic and intestinal tract disease in cats with pancreatitis. In cats with clinical signs of pancreatitis, serum fTLI concentration is poorly associated with histopathologic diagnosis.