Most of us have heard of the pancreas but aren’t really sure what it is.

Pancreatitis in the cat

Illustration by Wendy Brooks, DVM

Pancreas close up

Illustration by Wendy Brooks, DVM

The pancreas is a pale pink glandular organ nestled just under the stomach. It has two main functions: the endocrine function includes production of metabolic hormones (insulin and glucagon, which regulate blood sugar) while the exocrine function includes the production of digestive enzymes. These enzymes are secreted from the pancreas through a duct into the intestine where they help to digest food. In cats, the pancreatic duct frequently joins with the common bile duct from the liver, which means that both bile (a fluid used to excrete toxins as well as to prepare fat for absorption into our bodies) and pancreatic fluid, which is rich in digestive enzymes, enter the intestine from the same location. There are other hormonal products from the pancreas that assist in the regulation of digestion and movement of food but the above description is a basic overview of what the pancreas does.

Pancreatitis has the potential to be a serious condition. Here's why:

The normal pancreas has several safeguards in place to keep its digestive enyzmes securely stored. If these enzymes escape and become active, they will digest the body.  This is exactly what happens when the pancreas gets inflamed: the enzymes escape, become inappropriately activated and begin digesting the pancreas itself. The living tissue becomes further inflamed and the tissue damage quickly involves the adjacent liver. Toxins released from this rampage of tissue destruction are released into the circulation and can cause a body-wide inflammatory response. If the pancreas is affected enough to disrupt its ability to produce insulin, diabetes mellitus can result; this can be either temporary or permanent. It is also possible to develop exocrine pancreatic insufficiency (EPI) following pancreatitis.

Complications

Certain complications associated with pancreatitis include disrupting surfactants in the lung tissue that normally keep the tiny air-filled alveoli from collapsing after each exhaled breath. Without surfactants, the alveoli close up, and respiratory failure results.

In addition, fats throughout the body are destroyed in an event called the Weber-Christian syndrome. This is an inflammatory condition where the fat layer under the skin forms nodules that can lead to ulcers and openings on the top layer above them. This is also known as nodular panniculitis.

Pancreatitis is one of the chief risk factors for the development of what is called disseminated intravascular coagulation, or DIC, which is basically a massive uncoupling of normal blood clotting and clot-dissolving mechanisms. This leads to abnormal simultaneous bleeding and clotting of blood throughout the body.

Pancreatic encephalopathy (brain damage) can occur if the fats protecting the central nervous system become digested.

Pancreatitis can be acute or chronic with the chronic form more common (acute cases can reverse completely).

Pancreatitis can be mild or severe. Acute cases tend to be more severe and chronic cases tend to be milder. Mild cases may require little to no treatment. 

What Causes Pancreatitis in Cats?

Unfortunately, 90% of the time we never find out. We have some idea of possible risk factors, though.

• There may be an association between pancreatitis and inflammatory bowel disease. The theory is that abnormal intestinal disease leads to an overgrowth of bacteria. These bacteria can crawl up the pancreatic duct and cause infection in the pancreas.
  
  
• Trauma (getting hit by a car or falling from a great height).
  
  
• An active feline distemper infection.
  
  
• Toxoplasma (a parasite) infection can involve the pancreas, although it almost always involves other tissues as well.
  
  
• Pancreatic neoplasia. 
  
  
• Hypotension (low blood pressure) especially under anesthesia. 
  
  
• Organophosphate insecticide exposure. Organophosphates are not commonly used in flea control anymore but they are readily available in hardware and garden stores. They are also in some flea collars.
  
  
• Use of drugs; drugs have certainly caused pancreatitis in humans and dogs but have not been proven to be in cats. Still, with a cat with a history of pancreatitis, it is prudent to avoid drugs that have been associated with pancreatic inflammation. Such drugs include azathioprine (an immune suppressive agent), although it is uncommonly used in cats due to the risk of bone marrow suppression/myelotoxicity; thiazide diuretics, (furosemide); tetracycline (an antibiotic); valproic acid (a seizure control agent); and procainamide (a heart medicine).

Chances are the cause of pancreatitis for a given patient will never be determined.

If Your Cat Has Pancreatitis, What Might You Observe at Home?

In dogs and humans, this condition is associated with significant nausea and abdominal pain. According to one recent study in cats, though, only 35% of cats with pancreatitis showed vomiting and only 25% appeared to have abdominal pain. A fever is a possible sign but often the temperature will drop instead. Lethargy and appetite loss are consistent signs. Nearly all cats with pancreatitis lose their appetites, and about half of them will have been affected long enough to show weight loss.

Making the Diagnosis

The diagnosis of pancreatitis can be a challenging one, especially in chronic pancreatitis. All laboratory information and imaging as well as clinical information should be integrated. The diagnostic process has been aided by the development of the SPEC-FPL and PSL tests, which stand for Specific Feline Pancreatic Lipase and Pancreatic Sensitive Lipase respectively. The SPEC-FPL test can be run as an in-house test kit that yields a positive or negative or even a numeric value depending on the equipment used in a matter of minutes. The PrecisionPSL® test can be run by reference labs but does not have an in-house test kit.

These tests are based on the PLI test, which stands for Pancreatic Lipase Immunoreactivity, a test available through most veterinary hospitals. Lipase is one of the pancreatic digestive enzymes and small traces of it are normally in circulation. These levels increase dramatically during pancreatitis and thus the diagnosis can be made non-invasively without the expense of ultrasound. This form of testing is actually more sensitive than ultrasound which means it can detect pancreatitis in a milder state.

Of course, acute pancreatitis can be diagnosed on ultrasound because the inflamed pancreas becomes swollen and exhibits texture changes typical of inflammation. Chronic pancreatitis has more subtle sonographic findings.  Assessing the pancreas sonographically, however, depends on the operator's skill. Pancreatitis can also be diagnosed by biopsy during surgical exploration as well, though there is controversy as to whether removing a piece of the pancreas generates additional inflammation. The advantage of surgical exploration, however, is that other organs can be sampled to get a more complete picture of what is happening in the abdomen.

The SPEC-FPL and PrecisionPSL tests have become common additions to basic feline blood work and their elevations are commonly seen in cats with no symptoms of any kind. The significance of this suggests (but does not necessarily confirm) that the cat has an unhealthy bowel population, which has overgrown, and is either elaborating material that is inflaming the pancreas or has invaded the pancreas. If the cat genuinely has no symptoms, treatment is not necessary; however, it may be prudent to consider a hypoallergenic diet or the addition of probiotics (live cultures of beneficial bacteria) to the food to assist in recolonizing the bowel into a healthier microbe community.

How is the Cat Treated?

There are three parts to treatment: removing the cause of pancreatitis (this is usually not possible since the cause is only rarely known), general support and symptomatic relief through the inflammatory crisis, and monitoring and instituting protection against the serious complications listed above. Intravenous fluid therapy is used to support the pancreatic vasculature and combat any dehydration from vomiting or diarrhea. This simple act of perfusing the pancreas enables damaging inflammatory biochemicals to be flushed away and healing to begin.

Medications are used to control pain and nausea.  In the dog, high-fat diets are important predisposing factors for pancreatitis but this appears not to be true for cats. Pre-existing inflammatory bowel disease seems to bear more feline relevance so treatment in that direction seems more appropriate (steroids, antacids, low residue diets, or hypoallergenic diets).  Anecdotally, digestive enzyme supplementations are felt to be helpful in some cases. In the past, food restriction was included in treatment to rest the sensitive pancreas but newer thinking is that the entire GI tract heals faster when food is passing through it. Nutritional support is important in cats so that hepatic lipidosis does not develop.

Vitamin B12

The healthy pancreas manufactures a substance called intrinsic factor that is necessary for the absorption of vitamin B12 (cobalamin) from the diet. The unhealthy pancreas does not make enough intrinsic factor, and deficiency ensues when pancreatitis becomes chronic. This leads to an unthrifty and often anemic cat. Since dietary B12 cannot be absorbed without intrinsic factor, the traditional solution is to provide B12 by injection, usually at home, once or twice a week, and periodically thereafter. Vitamin B12 levels can be tested to determine if supplements are needed or, since the injections are relatively inexpensive and have a broad safety margin, sometimes they are simply prescribed without testing. A new oral B12 supplement has become available recently; its manufacturer claims to have solved the intestinal absorption problem.

Prognosis

How the cat does, in the long run, depends on how severely ill they are and what accompanying conditions exist. If the cat survives the episode of acute pancreatitis, there is a good chance that he or she will live a normal life thereafter. However, chronic cases of pancreatitis may wax and wane for years, requiring a permanent diet change and chronic medication administration.