Pancreatitis in Dogs
Cathy Meeks, DVM, DACVIM
Pancreatitis is an inflammation of the pancreas resulting in symptoms such as anorexia, vomiting, diarrhea and lethargy. The etiology is unknown; however, studies have suggested some factors may place dogs at a higher risk for developing pancreatitis (obesity, elevated triglycerides, diabetes mellitus, Cushing’s disease, high fat diets, certain drugs and trauma).
The major enzymes that digest food are located in pancreatic acinar cells, packaged in an inactive form called zymogens. Packaging these digestive enzymes in the inactive form prevents autodigestion of the pancreas. Zymogens are released into the duodenum where the enzymes are activated to allow normal breakdown of food. If zymogens are prematurely activated within the pancreas, the pancreas will inappropriately digest itself resulting in pancreatitis.
A CBC and chemistry should be done in all dogs with symptoms of pancreatitis. A neutrophilic leukocytosis is the most common finding on a CBC. The amylase and lipase may be elevated on the chemistry; however, this is not specific for the pancreas and can be seen in other diseases such as intestinal disease, liver disease and azotemia. Dogs with confirmed pancreatitis can also have normal amylase and lipase levels.
Canine pancreatic lipase immunoreactivity (cPLI) may be the most useful laboratory diagnostic test as cPLI measures lipase that only originates from the exocrine pancreas. Although this test is one of the most useful tests we have for pancreatitis, a recent study showed the SNAP cPL and cPLI results may provide a “false positive” diagnosis of pancreatitis in up to 40% of dogs presenting with acute abdominal disease. There was good overall agreement between SNAP cPL and cPLI; however, 10% of dogs with a positive SNAP cPL had a normal cPLI. Therefore, if a SNAP PL is positive, further diagnostics are warranted (such as cPLI and abdominal ultrasound), especially if the patient is not responding to therapy.
Abdominal ultrasonography is another way of screening for pancreatitis and ruling out other possible causes of an elevated PLI, including pancreatic neoplasia, pancreatic abscess, etc. In acute cases, an enlarged hypoechoic pancreas is often surrounded by a hyperechoic area that is due to fat necrosis. Peritoneal effusion is also a common finding in pancreatitis.
There are no specific treatments for pancreatitis, and therapy is aimed at controlling the symptoms. Fluid therapy (crystalloids +/- colloids), pain medications and anti-nausea medications are most important in the patients’ recovery. In cases that require hospitalization, careful monitoring of the electrolytes and albumin are essential to prevent complications. Feeding patients with pancreatitis has been controversial; however, a recent study showed early enteral nutrition delivered proximal to the duodenum (such as with nasoesophageal feeding) was well tolerated and resulted in less complications than parenteral nutrition.
Extrahepatic biliary tract obstruction (EHBO) can occur with acute pancreatitis. This often resolves spontaneously as the acute pancreatitis improves; although, in rare cases surgery is necessary. Acute pancreatitis may also result in respiratory difficulty due to pleural effusion (from low albumin and/or vasculitis), pulmonary edema (as can be seen with acute respiratory distress syndrome) and pulmonary thromboembolism. In some cases, pancreatitis can be severe, resulting in an abscess or necrotizing pancreatitis that may require surgical intervention. Chronic pancreatitis may result in exocrine pancreatic insufficiency and diabetes mellitus.
There is currently no specific test for pancreatitis in dogs, and diagnosis should be based on a combination of compatible clinical, clinicopathological and imaging findings. Amylase and lipase can be useful in the diagnosis of pancreatitis; however, there are other causes of elevations in these enzymes, and normal enzyme concentrations do not rule out pancreatitis. Abdominal ultrasound has assumed a major role in the diagnosis of pancreatitis and the differentiation of pancreatitis from other pancreatic disorders. The prognosis depends on the severity of disease with mild disease having a good prognosis and severe or recurrent pancreatitis having a guarded prognosis.