Lipase (total and DGGR) in cats and dogs

What it shows

A biochemistry panel measures lipase activity — how fast the sample breaks down a test fat, the substrate. The result depends heavily on which substrate is used. Older methods use a 1,2-diglyceride, and lipases from many tissues react with it. This is the row usually labelled simply “Lipase” or “total lipase”.

The DGGR method uses a different substrate (the abbreviation comes from its long chemical name), with a detergent and colipase added to make it more specific for pancreatic lipase. On a form it may appear as “Lipase (DGGR)”. Merck describes an in-house DGGR assay as specific; eClinPath adds that it still reacts in dogs whose pancreas produces no enzymes, so other lipases take part. Neither row is the same as pancreatic lipase immunoreactivity (Spec cPL, Spec fPL), which detects the pancreatic enzyme itself with antibodies — see pancreatic lipase.

Higher than reference — what it may be a sign of

• Pancreatitis: the main reason to measure it. eClinPath notes that rises of 3 times the reference limit supported pancreatitis more strongly than moderate ones.
• Reduced kidney filtration: with the 1,2-diglyceride method, lipase can rise up to 4 times with decreased filtration, and in an animal with high kidney values pancreatitis is still considered above 3–4 times. With DGGR, lipase is not always increased even with very high kidney values in dogs.
• Corticosteroids: reported to raise lipase measured with the 1,2-diglyceride method.
• Gut and abdominal conditions: peritonitis, gastritis, bowel obstruction and abdominal surgery may increase lipase; DGGR lipase may be raised in dogs with gastrointestinal disease.
• Other causes: liver disease and tumours (older method), and heparin given to the animal.

Lower than reference

A low lipase is not how vets look for a pancreas that produces too few enzymes (exocrine pancreatic insufficiency): Merck describes serum trypsin-like immunoreactivity (TLI) as the test for that. eClinPath notes that dogs with this condition can still show activity in the DGGR assay — one more sign that activity methods also measure lipases from outside the pancreas.

Look at together with

• Pancreatic lipase — specific to the pancreas; used to confirm or argue against pancreatitis.
• Amylase — rises and falls in parallel in acute pancreatitis; Merck gives a specificity of only about 50% for both in dogs.
• Creatinine and urea — when they are high, a raised total lipase may partly come from the kidneys.
• Triglycerides — in dogs severe hypertriglyceridemia is a risk factor for pancreatitis.

Units and conversion

Both rows are enzyme activity in units per litre — U/L on English forms, Ед/л or МЕ/л on Russian ones — so there is nothing to convert. But total lipase and DGGR lipase are different methods with different reference ranges: a value from one cannot be compared with the other, even in the same unit. That is why the app keeps them as two separate indicators.

Reference range

The reference range is on your lab’s form. It belongs to a specific method and analyser: IDEXX material by Steiner and Cridge points out that even assays using the same substrate may produce completely different results. Vets usually describe a rise as a multiple of the upper limit and judge it together with signs, kidney values and, when needed, pancreatic lipase and ultrasound.

Cats and dogs

Sources

1. eClinPath (Cornell University College of Veterinary Medicine) — Lipase
2. Steiner JM. Pancreatitis in Dogs and Cats. Merck Veterinary Manual
3. Whitbread TJ. Clinical Biochemistry. Merck Veterinary Manual
4. Steiner JM. Exocrine Pancreatic Insufficiency in Dogs and Cats. Merck Veterinary Manual
5. Steiner J, Cridge H. Acute Pancreatitis — Diagnosis & Management. IDEXX