Many years ago, when I was doing my residency in small animal internal medicine, I had a conversation over lunch with one of the small animal surgery residents. I asked him how he was holding up during his grueling course of study “Well, I think I discovered the three rules to surviving this surgery residency,” he told me. “Eat when you can, sleep when you can and don’t mess with the pancreas.”
The pancreas is a small organ, but it performs some pretty big duties. Shaped roughly like an upside down V, the pancreas sits nestled up against the stomach. The pancreas has a dual role as an organ. It is an “endocrine” organ, producing essential hormones such as insulin and glucagon, which are released directly into the bloodstream, helping to regulate the blood sugar level. It is also an “exocrine” organ, involved in the production of digestive enzymes. These are released directly into the small intestine and are essential for the proper digestion of dietary proteins, fats and carbohydrates.
Although my colleague was being facetious with his comment about not making the pancreas angry, there is much wisdom behind those words. A cat’s good health depends on a properly functioning pancreas.
As with all organs in the body, the pancreas can occasionally malfunction. The endocrine portion can malfunction, resulting in diabetes. This occurs when the pancreas either produces an inadequate amount of insulin or fails to secrete insulin in the proper manner.
The exocrine portion of the pancreas can also malfunction, leading to another important pancreatic disorder: pancreatitis, an inflammation of the pancreas. Normally, digestive enzymes are sequestered in tiny protective droplets that prevent them from coming into direct contact with pancreatic tissue, until they can be secreted into the small intestine where digestion of nutrients occurs.
Pancreatitis occurs when digestive enzymes become activated early and begin the digestive process while still inside the pancreas. Because the pancreas itself is composed of fat, protein and carbohydrate, the organ may start to feed upon itself. Exactly why this occurs is not fully understood. Potential triggers for pancreatitis in cats include infection, trauma, parasitism and inappropriate reactions to certain drugs. In most cases (greater than 95%), however, a specific cause isn’t identified.
When dogs get pancreatitis, vomiting and abdominal pain are the most common signs. In cats, however, the signs vary considerably. Only about one-third of cats with pancreatitis will vomit, and only one-quarter show abdominal pain. Instead, lethargy, poor appetite and dehydration top the list of signs of feline pancreatitis.
Diagnosing pancreatitis has always been a challenging task for veterinarians. A diagnosis cannot be made based solely on historical or clinical findings, because the common symptoms — lethargy, poor appetite, weight loss, vomiting, diarrhea — mimic many other diseases.
An additional complication is that in cats, pancreatitis often develops concurrently with other diseases, most notably hepatic lipidosis (fatty liver disease) and inflammatory bowel disease. (In fact, the simultaneous occurrence of these three disorders is frequent enough to warrant its own name — “feline triad disease” or “triaditis.”)
The pancreas is not readily identifiable on X-rays, so radiographs are rarely helpful in the diagnosis. Ultrasound is a better diagnostic test, but it is expensive, and the results are highly dependent on the skill of the ultrasonographer and the severity of the inflammation.
The common blood and urine tests we perform on sick cats — a complete blood count (CBC), serum biochemistry panel and urinalysis — give us important information but are not specifically diagnostic for pancreatitis. Affected cats may have an elevated white blood cell count, a slightly elevated blood sugar, a mildly decreased calcium level and moderately elevated liver enzymes, but these findings are variable and inconsistent.
Years ago, it had been suggested that two enzymes found in serum, amylase and lipase, were good indicators of pancreatic inflammation in dogs if they were elevated, and the same was assumed for cats. These enzymes were actually not very specific for canine pancreatitis (almost 50% of dogs with elevated amylase and lipase levels did not have pancreatitis), and for cats the situation was even less reliable. As it turns out, serum amylase and lipase levels are unhelpful for diagnosing feline pancreatitis.
More sensitive blood test
The lack of a simple and reliable blood test specifically for pancreatitis was a frustrating problem for veterinarians and undoubtedly was responsible for the disorder being underdiagnosed (or misdiagnosed entirely). However, the development of a much more sensitive blood test, the feline pancreatic lipase immunoreactivity (fPLI) test, has greatly improved our ability to diagnose.
Normal cats have low levels of fPLI circulating in their bloodstream. Cats with pancreatitis typically show significant elevations of their fPLI levels. The test is now routinely performed at veterinary diagnostic laboratories, and there is even an in-house test that can be performed at the veterinary hospital while the client waits.
Treatment can be tricky
There is no magic drug to treat feline pancreatitis. Therapy for pancreatitis is mainly supportive and symptomatic. Intravenous fluid therapy is necessary to prevent dehydration resulting from fluid loss from vomiting and/or diarrhea and to ensure that the pancreas is well perfused with blood.
If nausea or vomiting is present, the use of anti-nausea drugs is warranted. Abdominal discomfort is a common component of pancreatitis in dogs. Cats tend to be secretive about showing signs of pain, but it is presumed that they experience the same type of discomfort, so the use of pain medication is typically part of the treatment. The anti-nausea drug maropitant is an excellent drug for cats with pancreatitis because it can be given via injection rather than orally.
The drug is also believed to have an analgesic effect on the abdominal organs, an added bonus.
Antibiotics are generally not administered. This is because infection is not believed to be a significant component in pancreatitis.
As with most debilitating illnesses, nutritional support is an important component of therapy. Cats with pancreatitis often refuse to eat. An appetite stimulant should be given to these cats, as restoring food intake is a critical factor in recovery.
If cats continue to refuse food even after administration of appetite stimulants, tube feeding should be considered. This can be done through the use of a nasoesophageal tube (a thin tube that reaches the esophagus by way of the nose) or an esophagostomy tube (a tube that enters the esophagus, through a small incision created on the side of the cat’s neck.)
The nasal tube can be inserted using only a local anesthetic, but with the nasal tube, you’re limited to giving a liquid diet, and cats really dislike having a tube in their nose. Cats tolerate esophagostomy tubes much better, and cats can be fed canned diets as a gruel, but placement of the tube requires general anesthesia.
How the disorder progresses varies from cat to cat. Most cats develop acute cases of pancreatitis — their perfectly normal pancreas suddenly becomes inflamed, the cat becomes pretty sick and hospitalization is required. The cat often recovers and never experiences a problem with the pancreas again.
A small (but significant) percentage of cats, however, will recover from an initial acute attack and then develop chronic pancreatitis, a constant low level of pancreatic inflammation which will flare up intermittently. Over time, the chronic inflammation can lead to gradual scarring of the pancreatic tissue, which could eventually take its toll on the organ’s ability to function.
Sadly, a small percentage of cats with pancreatitis do succumb to their illness, but with the advent of better diagnostic tests, highly effective appetite stimulants, improved pain management medications and routine use of feeding tubes, the prognosis for cats with pancreatitis has improved, and most cats do recover.
Pancreatitis signs in cats
The following are clinical signs and physical exam findings in cats with pancreatitis:
SIGN / % AFFECTED
Lethargy / 100%
Poor appetite / 97%
Dehydration / 92%
Rapid breathing rate / 74%
Low body temperature / 68%
Jaundice / 64%
Rapid heart rate / 48%
Vomiting / 35%
Abdominal pain / 25%
Abdominal mass felt on physical exam / 23%
Labored breathing / 20%
Diarrhea / 15%
Incoordination / 15%
Fever / 7%