Pancreatitis testing -where are we now and why do blood results and ultrasound findings not agree?
This is a major issue for sonographers because suspect pancreatitis is a very common reason for scan requests. ….and my experience is that the scan results frequently don’t agree with blood results. The paper below (Kook et al.) is worth a read because it’s written by independent authors with no commercial interest in any particular lab test.
Summary of Kook et al.:
-there is no gold standard diagnostic test in cats or dogs. Even histopathology is unreliable because localised disease is common. It’s impossible at present to rule out pancreatitis ante mortem. Because of this no-one can be sure of sensitivity/specificity (this is my interpretation anyway – although apparently Bayesian statistics have been used to circumvent the problem…if you believe in that kind of thing: it’s a bit like reconstructing dinosaurs from one toe bone).
-lipase by DGGR (which is now the test used by IDEXX and NWL as standard -if you ask for a plain ‘lipase’ -this replaced old lipase test a few years ago) and IDEXX’s spec cPL or fPL have very good agreement with each other -although we currently have only one paper for each species showing this. Since lipase is relatively cheap and can be done same day there is a good case for just using lipase.
-lab tests (snap cPL/fPL, spec cPL/fPL) have relatively poor agreement with ultrasonography. No-one knows which is ‘right’. It probably depends on things like whether the pancreatitis is acute/chronic/bit of both, whether immune-mediated pancreatitis or not (especially Cockers and spaniels generally) and other factors. Personally I think this probably has quite a long way to run. Texas A&M are running a trial treating some subsets of pancreatitis dogs with cyclosporine.
CT angiography is gold standard in people. If you have access to it.
Another interesting aspect is the clinical difference between dogs with left lobe pancreatitis and those with right lobe pancreatitis. Left lobe ones don’t vomit (usually) because duodenum not involved.
So, it’s not a surprise if we see animals where clinical picture, lab results and scan findings don’t match up. There just isn’t a definitive answer for these. My reading of the situation is that we just have to generate our own index of suspicion for pancreatitis in each case and treat accordingly.
Kook et al. JVIM 2014: Dogs, comparison of DGGR lipase and spec cPL/SNAP cPL) and comparison of both with ultrasonographic findings.
Oppliger et al JAVMA 2014: Cats: comparison of DGGR lipase and spec cPL/SNAP cPL) and comparison of both with ultrasonographic findings.
Oppliger JVIM 2013: Cats, comparison of DGGR lipase with spec fPL