Canine Pancreatitis: The Master of Disguise
Presenter – Professor Mike D. Willard DVM, MS, Diplomate ACVIM (SA Internal Medicine) from The Texas A&M University College of Veterinary Medicine & Biomedical Sciences
After watching Professor Willard speaking at last week’s webinar, I now have a far greater understanding of why diagnosing canine pancreatitis can be so challenging. The fact is that many of these cases just don’t follow the rulebook.
History taking is such an important process in any diagnostic work up, but just because we are presented with a vomiting middle-aged overweight female schnauzer, doesn’t necessarily mean she is suffering from pancreatitis.
As Professor Willard stated, history is neither sensitive nor specific for pancreatitis and the same also applies for physical examination. We might expect to find cranial abdominal pain but there are plenty of other conditions that may present similarly – how about a foreign body or a gastric ulcer?
And what about lab work? Maybe this could prove more useful in the quest to diagnose canine pancreatitis? Professor Willard showed us haematological findings from several cases and asked us which we thought were suffering from pancreatitis. Despite the enormous variation in values, of course they all were. This makes haematology, although necessary, not specific or sensitive enough to diagnose pancreatitis.
Biochemistry results can also be unhelpful and Professor Willard was particularly damning of measuring amylase and lipase levels as their specificity and sensitivity of around 50% makes them poor indicators of pancreatitis – so much so, that Professor Willard refuses to let his students perform these tests.
At this point I was starting to become a little concerned that no test was likely to positively diagnose canine pancreatitis, but to my great relief, Professor Willard went on to show there might be light at the end of the tunnel. The cPLi test has around 80-85% sensitivity, so if this test proves negative, it is fair to start looking for other possible causes. However, if the test proves positive, Professor Willard advised that the clinical signs are likely to be caused by pancreatitis, but this is not always necessarily the case. He warned that although having such a sensitive test is highly useful there is always a possibility that this test could prove positive even with very minor and clinically insignificant changes within the pancreas.
Diagnostic imaging is extremely useful in diagnosing pancreatitis and ultrasound can be especially helpful. Professor Willard was keen to advocate the repeated use of ultrasound on a single case, as a normal looking pancreas on ultrasound at one point can look completely different within the space of a few hours. So not only will repeat ultrasounds help to exclude other potential causes of a patient’s clinical signs, it will also help to ensure that pancreatitis has not been missed.
So I now think I’m safe to make the assumption that after performing a battery of tests, a diagnosis of pancreatitis should be fairly easy to make. Typically though, this is not the case. Professor Willard discussed that even after all these tests, pancreatitis is great at ‘pulling the wool over our eyes’ and disguising itself as other conditions. Even with his experience and knowledge Professor Willard cited several occasions where he mistook pancreatitis to be another condition, including pyometra and septic peritonitis. So we were advised that at some point in our career we were bound to be caught out by this challenging condition, and to always beware of the ‘master of disguise’.
The Stethoscope (MRCVS)