Pancreatitis is recognized as an important and common problem in dogs, but diagnosis can be challenging. Recently, new assays for the measurement of trypsin-a1-proteinase inhibitor complexes and canine pancreatic lipase immunoreactivity (cPLI and Spec cPL) have been developed and analytically validated. This is the first report of a direct comparison of the sensitivity of these and other more traditional serum markers for the diagnosis of canine pancreatitis in a subset of dogs with this disease (i.e., dogs with both macroscopic and microscopic changes characteristic of pancreatitis). Serum cPLI and Spec cPL concentrations showed the highest sensitivity for the diagnosis of pancreatitis in this group of patients. Further studies will be required to compare the specificity of these serum markers and thus determine their overall clinical utility.