advances in diagnostics: the snap fpl test
We’ve talked before about pancreatitis, or inflammation of the pancreas, and how hard it is to definitively diagnose. This is especially true in the cat, because often times our feline friends present with non-specific clinical signs. Pancreatitis in cats can be acute, meaning that it crops up all of a sudden, or it can be a chronic smoldering problem that goes on for months or more.
Cats with pancreatitis may present with lethargy and a decreased appetite, which are common symptoms for many illnesses. Some patients have been vomiting, while others have not. Diarrhea, fever, and jaundice are also symptoms of pancreatitis, but are nonspecific for this disease.
Pancreatitis often occurs on top of other diseases, such as inflammatory bowel disease, hepatic lipidosis, cholangitis, or diabetes, further complicating the diagnosis. When one of these other diseases is found, often the hunt for illness stops so the underlying pancreatitis might be missed.
The need to correctly diagnose pancreatitis is dire, as pancreatitis can become so severe that it can be life-threatening. An inflamed pancreas can leak digestive enzymes, causing further damage to the pancreatic tissue and its neighbor, the liver. When tissue destruction occurs, toxins are released into the bloodstream, resulting in a widespread inflammatory response. All of this leads to one very sick kitty.
Routine bloodwork will be nonspecific. A complete blood count (CBC) may show anemia or signs of dehydration, but this is true of many diseases. A chemistry panel will likely show increases in liver and kidney enzymes as well as electrolyte imbalances, but, again, this could be interpreted many ways. Unfortunately, the pancreatic enzymes amylase and lipase may or may not be elevated, and are of little diagnostic value. So, then, how do we diagnose this terrible disease?
In the past, we have had to rely on our intuition, mostly. We can utilize diagnostics, such as x-rays and ultrasounds, together with the patient’s symptoms and hope to arrive at a diagnosis of pancreatitis, but without a biopsy, it can be hard to be sure. However, a relatively new test has emerged that could tip the odds in our diagnostic favor.
IDEXX laboratories has developed a diagnostic tool called the SNAP fPL test that measures the levels of lipase in your cat’s blood that is specific to the pancreas. While the test doesn’t give an exact measurement of the level of pancreatic lipase, it does indicate whether the level is higher than the cut-off we would expect in a normal patient. Elevated levels of pancreatic lipase would indicate pancreatitis.
The test takes about 10 minutes to run, and while it’s not perfect, it can help veterinarians diagnose pancreatitis or feel confident in ruling it out as an explanation of a patient’s clinical signs. A recent study has shown that the test is 79% accurate in picking up cases of pancreatitis when it is there and 80% accurate in ruling it out if it is not present.
The sooner pancreatitis is found, the sooner we can work on making your cat feel better. And the sooner he feels better, the sooner he can come home to you, so we welcome this new tool in our diagnostic arsenal.