Acute pancreatitis (AP) is a common disorder characterized by the inflammation of the exocrine pancreas in dogs, and the severity of the clinical signs of pancreatitis varies greatly. Therefore, the diagnosis of pancreatitis is challenging. The canine pancreatic lipase immunoreactivity test (SNAP cPL; IDEXX Laboratories Inc., USA) is rapid and relatively accurate in diagnosing pancreatitis. The purpose of this study was to evaluate the positivity rate of the SNAP cPL test in dogs regarding the severity of gastrointestinal (GI) signs and concurrent diseases. Electronic medical records of dogs were reviewed. For retrospective classification, 80 dogs with GI signs who underwent the SNAP cPL test were enrolled. Additionally, concurrent diseases on the day of the SNAP cPL test were reviewed. A positive SNAP cPL test result was observed in 26 of the 80 dogs (32.5%) with GI signs. The severity of GI signs using a scoring system and the positivity rate of SNAP cPL were statistically related. Furthermore, dogs with concurrent chronic kidney disease had a significantly higher positivity rate of SNAP cPL than those without chronic kidney disease. This information might help clinicians to decide whether a SNAP cPL test is needed.