Pancreatitis in Cats
The pancreas is an important, if often overlooked, organ that is adjacent to the stomach. It is fairly small, but loss of pancreatic function can cause life-threatening complications.
The organ itself has two functions. The first is an endocrine function, in which it synthesizes the insulin and glucagon hormones. These are important for regulating proper blood sugar levels. It also has an exocrine function that produces and secretes enzymes, which aid in the digestion of food.
What Is Pancreatitis?
Pancreatitis is the most common illness of the exocrine pancreas in cats. It is an inflammation caused by digestive enzymes becoming activated inappropriately and breaking down the pancreatic tissue. These enzymes are inactive until they are released to the duodenum, the first section of the small intestine, to digest food. In some cases, these enzymes are activated too early and begin to digest the only tissue near them, which is the pancreas itself. This can cause severe inflammation.
Pancreatitis can either be acute or chronic. Chronic pancreatitis often goes unnoticed, as the signs are vague and other diseases may mask the symptoms. One study showed that 67% of feline pancreatic tissue that was examined postmortem showed signs of chronic pancreatitis, even though 45% of cats had appeared healthy while alive.
Acute pancreatitis comes on suddenly, and severe cases can be life threatening. Cats who do recover from acute cases of pancreatitis often develop the chronic form of the disease, which can cause dysfunction within the organ over time.
Causes and Risk Factors
Animals of any age, gender, or breed can be diagnosed with pancreatitis. The disease seems to be more prevalent in cats over the age of 7 years old, but it may be recognized in cats of all ages.
Most cases of pancreatitis have no obvious cause (idiopathic). It is suspected that concurrent disease may play a part in the development of pancreatitis, particularly irritable bowel syndrome. Episodes of ischemia (lack of blood flow) within the pancreas, such as during an anesthetic event, may also be a predisposing factor.
In dogs, a diet high in fat or dietary indiscretions, where the pet has eaten a large amount of fatty food, are often correlated with cases of acute pancreatitis. There is no proof that this is a cause in cats, but it may be a complicating factor.
Symptoms of Pancreatitis
The symptoms of pancreatitis are very vague and are often similar to other disease states, making it very difficult to diagnose in cats.
Common signs include:
- Loss of appetite (inappetence)
- Increased respiratory rate (tachypnea) or difficulty breathing (dyspnea)
Complications of Pancreatitis
Pancreatitis can also lead to other disease processes that can complicate an animal’s recovery. Inappetence associated with pancreatitis can cause hepatic lipidosis, a potentially fatal disease affecting the liver.
Breakdown of the pancreatic tissue may also cause a problem with the endocrine portion of the pancreas, which produces the hormones needed to balance blood glucose (BG) levels. If the body is unable to maintain proper BG levels, hyperglycemia occurs. This is a state of increased blood glucose, which often results in diabetes mellitus, a disease process in which the body is unable to produce insulin. In acute cases of pancreatitis, this may be a transient process that can be reversed once the incident is over. Chronic cases of pancreatitis will often result in a cat becoming diabetic and needing management at home for the disease.
Occasionally, activated digestive enzymes migrate to the liver and intestines, causing inflammation in those organs. This multi-organ inflammation is known as triaditis. In extreme cases, triaditis can lead to bacterial translocation, causing bacteria to enter the cat’s bloodstream, leading to sepsis or a very serious complication known as disseminated intravascular coagulation (DIC). DIC causes a breakdown in the body’s coagulation process, leading to extreme clotting of the blood and internal bleeding.
In the end stages of chronic pancreatitis, the pancreas may be unable to produce and secrete the digestive enzymes needed to help the body digest food, a condition known as endocrine pancreatic insufficiency.
Diagnosis of Pancreatitis
Pancreatitis is difficult to diagnose, due to a wide variety of clinical symptoms. When a cat presents symptoms and is brought to the hospital, the medical staff will conduct a full examination and get a complete medical history from the owner. When speaking to the veterinarian or technician, it is important to share all of your pet’s symptoms. Though symptoms like loss of appetite, vomiting, and lethargy may be associated with many different diseases, your vet’s knowledge of common symptoms can help determine the underlying cause.
Once your cat has been examined, the veterinarian will recommend tests to help make a diagnosis. These will likely include full bloodwork and an ultrasound.
A blood panel will be completed to review small and nonspecific changes. These tests are usually helpful in ruling out other causes of a cat’s symptoms, and to diagnose concurrent diseases.
Serum feline pancreatic lipase immunoreactivity (fPLI) is the most useful test for diagnosis of pancreatitis. It measures the levels of pancreatic secretions in the blood. Levels higher than 5.4 mcg/L are considered diagnostic for feline pancreatitis.
There are two types fPLI tests. The first is known as a SNAP test. The SNAP test can be conducted in a clinic over a relatively brief period of time, and will read positive if the secretion levels in the blood are 3.5 mcg/L or higher, which is considered the “gray zone.” If the SNAP test comes back positive, it is necessary to send blood to an outside lab to run a more specific fPLI test to confirm the diagnosis.
Ultrasonography is helpful in recognizing changes in the pancreas that are indicative of pancreatitis, and is a simple and non-invasive test. The most definitive test for diagnosing pancreatitis is a pancreatic biopsy. This must be done under general anesthesia, unless the animal is too ill to be anesthetized. More often, an aspirate of the pancreas will be taken using a needle. This is not as reliable as a biopsy, as it is possible to get a sample of the pancreas that does not contain inflammatory cells.
Due to the risk in obtaining a biopsy to fully confirm a diagnosis of pancreatitis, this disease is most often diagnosed when all other reasons for clinical symptoms have been ruled out, and in consideration of concurrent disease processes.
Treatment of Pancreatitis
Treatment of pancreatitis needs to be started as soon as the disease is suspected. Cats who are having an acute attack need to be hospitalized, while cats with chronic disease may be able to be managed at home. If there are concurrent diseases, these must also be treated and may affect the length of time the cat needs to be hospitalized.
The patient will have an intravenous catheter placed for fluid administration. These animals are usually dehydrated due to inappetence and vomiting, so rehydrating is an important step in making them feel better. If there are any electrolyte abnormalities that have been identified in the blood work, fluids may need to be supplemented with medications to correct these abnormalities.
While humans and dogs with pancreatitis often show signs of abdominal pain, this is less commonly noted in cats. Cats are naturally stoic when in pain, which makes it difficult to recognize if they are uncomfortable. It seems likely that cats with acute pancreatitis do feel discomfort and it is common practice to provide pain medication. Usually, the pain is managed with an opioid such as buprenorphine or fentanyl.
Other medications often given include antiemetics to prevent nausea and gastroprotectants to protect the mucosal lining of the GI tract.
Feeding During Treatment
Historically, patients with pancreatitis have food withheld for 24 – 48 hours to allow the pancreas to heal. This practice is no longer considered appropriate, as it has been proven that starting food early actually helps a patient recover more quickly. Ideally, with proper pain and nausea control, the cat will voluntarily eat. Syringe or force feeding is not recommended, as it can cause a food aversion and make cats less likely to want to eat. If an animal will not eat, giving an appetite stimulant can help. If after receiving the appetite stimulant the cat still does not want to eat, it may be necessary to place a feeding tube in order to provide appropriate nutrition.
Prognosis for cats with severe acute pancreatitis is guarded. With early treatment, the cat may recover fully and never have a problem again. Patients with concurrent disease may have more serious complications that decrease their ability to recover.
Chronic pancreatitis may not cause any obvious symptoms, but in cats where it is a known disease, long-term management is needed. This often means regulation of coexisting diseases. The appropriate management of these conditions will have a direct impact on the cat’s prognosis.