The laboratory diagnosis of pancreatic disease in dogs and cats has taken has made some significant progress in the last few years. Exocrine pancreatic insufficiency (EPI) is now recognised in both dogs and cats and while most affected animals are young there are a number of older animals that are affected. The canine Trypsin-Like Immunoreactivity (TLI) test is both sensitive and specific for EPI and is assayed as part of the canine intestinal profile together with folate and cobalamin. Feline TLI has been shown similarly to be an excellent assay for EPI in cats, however this test is currently available only in the USA. As a result, we do not routinely include this test in the feline intestinal profile but we would recommend adding it for all cats with steathorreic faeces and for cats that are thin despite eating well where other causes have been ruled out.
The laboratory diagnosis of canine pancreatitis is complicated by the fact that amylase and lipase quickly return to normal following the onset of clinical signs – so normal results need not exclude pancreatitis. In addition, mild increases in amylase and lipase can be seen with intestinal and hepatic disease and both are affected by reduced renal function. As a result these tests are neither completely sensitive nor specific.
In cats with pancreatitis amylase and lipase are only occasionally abnormal and they are considered of little diagnostic value in this species.
Pancreatic lipase immunoreactivity (PLI) however, holds out considerably more promise for the diagnosis of pancreatitis in the dog and cat. In dogs, PLI elevations appear to persist for longer than other tests and this is now considered the best test for chronic pancreatitis. In cats with pancreatitis, PLI has been reported to be more sensitive than TLI (70% vs. 30%). This is particularly useful in cats as the clinical signs in this species are often non-specific (lethargy, anorexia, dehydration) with only 35% showing vomiting and 25% showing abdominal pain.
Currently the PLI assay is only available in the USA so the turnaround is about 10 days. It is likely however that we will be able to offer this assay more directly in future. To request PLI for dogs or cats simply indicate this on the request form (B33) and ensure that an additional 0.75 ml non-lipaemic serum is submitted.

About the Author

Nick graduated from Edinburgh Veterinary School in 1980 with an
Honours degree in Pathological Sciences and in 1982 as a Bachelor
of Veterinary Medicine and Surgery. In 2003 Nick became a diplomate
of the Royal college of Pathologists in veterinary clinical pathology.