Pancreatic Exocrine Neoplasia in Dogs

Overview of Canine Pancreatic Exocrine Neoplasia

Exocrine tumors of the pancreas are tumors that arise from the glandular tissue of the pancreas that produces digestive secretions. Most of these tumors are malignant (adenocarcinomas). Benign exocrine pancreatic tumors are extremely rare in dogs.

There is no known underlying cause. They occur more commonly in older dogs. Airdales and boxers may be at a higher risk for this tumor. They are slightly more common in cats than dogs.

Exocrine tumors of the pancreas are aggressive tumors that invade nearby tissues and spread to distant organs. The clinical signs of exocrine pancreatic cancer cannot be differentiated from the clinical signs of benign pancreatic disease. The outlook for this disease is extremely poor with most dogs and cats surviving for less than three months following diagnosis.

What to Watch For

Signs of pancreatic exocrine neoplasia in dogs may include:

An acute or chronic history of:

• Vomiting
• Abdominal pain
• Anorexia
• Weight loss and lethargy

Diagnosis of Pancreatic Exocrine Neoplasia in Dogs

• Your veterinarian will palpate your pet’s abdomen, feeling for pain, distension or even the presence of a lump or mass. Some animals may show signs of jaundice because a pancreatic tumor can obstruct the flow of bile from the liver to the small intestine resulting in elevated levels of bile products in the blood causing the skin and mucous membranes to appear yellow.
• X-rays may help to confirm the presence of a pancreatic disease and sometimes can help to define the presence of a mass on the pancreas. Ultrasonography is usually far more specific to detect types of pancreatic disease but this test needs to be performed by an experienced ultrasonographer.
• Laboratory findings may be consistent with bile outflow obstruction, dehydration and the body’s normal response of inflammation without being specific for a pancreatic exocrine tumor.

Treatment of Pancreatic Exocrine Neoplasia in Dogs

• Medical management of animals with exocrine pancreatic neoplasia is generally unrewarding as these tumors are not particularly responsive to chemotherapeutic agents.
• Surgery is the treatment of choice, although the tumor has usually advanced by the time of diagnosis making resection difficult. Sometimes, the tumor has spread to organs such as the local lymph nodes, spleen and liver at the time of surgery.
• The majority of dogs and cats that have exocrine pancreatic neoplasia confirmed at the time of surgery are put to sleep while under general anesthesia due to the poor prognosis for this disease.

Home Care and Prevention

On rare occasions when there is no obvious evidence of spread to other organs, an exocrine pancreatic tumor can be removed, and your pet may recover from the surgery.

Hospitalization in an intensive care unit is usually required for several days following the procedure. Intravenous fluids are supported by food given intravenously or via a feeding tube to the small intestine, placed at the time of surgery.

Feeding tubes must stay in place for at least 5 to 7 days following surgery so feeding and tube management may continue for some time once your pet comes home. Offering food and water by mouth may be delayed for several days following surgery. Postoperative antibiotic treatment is not routine for animals with pancreatic tumors.

There is no known underlying cause for pancreatic exocrine neoplasia and therefore no way to preempt the disease. Taking a middle aged or older pet with a history of vomiting, weight loss and perhaps abdominal pain, to your veterinarian at the earliest opportunity is best action you can take. Having said this, exocrine pancreatic tumors are a bad disease, and the prognosis is generally extremely poor.

In-depth Information on Pancreatic Exocrine Neoplasia in Dogs

The clinical signs for exocrine pancreatic neoplasia are the same as for many other diseases, some of which carry a much more favorable prognosis.

• Abdominal pain could derive from an array of potentially life threatening disorders such as a septic peritonitis, which is a bacterial infection of the lining of the abdomen, arising from a perforated loop of bowel, a ruptured gall bladder or an abscess on the spleen, liver, pancreas, prostate or kidney. X-rays and ultrasound are helpful in recognizing these disorders.
• Non-infectious causes of abdominal pain, which may be accompanied by abdominal distension, include acute or chronic pancreatitis, gastric dilatation and volvulus (GDV), mesenteric volvulus, interssusception or other form of intestinal obstruction. Plain X-rays may be the only diagnostic tool necessary to define the gastrointestinal disorders. Pancreatitis can be appreciated by ultrasound in the hands of a skilled ultrasonographer.
• Disorders of the spine, such as a herniated intervertebral disk or an infection involving the disk known as diskospondylitis, can mimic pancreatic disease by creating abdominal guarding or splinting with a sense of pain on abdominal palpation. Careful physical examination and lack of finding on abdominal X-rays or ultrasound would steer your vet toward a spinal problem.
• Urinary tract disorders such as inflammation of the bladder (cystitis) or urethral obstruction can create abdominal pain that can be misinterpreted as a pancreatic problem. These urogenital abnormalities would become apparent during the work-up of the case.
• Vomiting and anorexia are seen in cases of pancreatic exocrine neoplasia and are clinical signs for a huge list of common non-pancreatic disorders such as dietary indiscretion and viral, bacterial or parasitic gastroenteritis. The signs demonstrated by your cat and dog will be pieced together with your pet’s signalment and history. Not every vomiting cat or dog is going to require a long list of diagnostic tests.

In-depth Information on diagnosis

• Your dog’s problems may have been of short (acute) or long (chronic) duration. Going off food and losing a significant amount of weight can be difficult to appreciate for many animals unless weight is actually measured on a regular basis.
• On physical examination your pet may show discomfort when palpated in the upper right quadrant of the abdomen. In some cases the abdomen will be tense and painful all over. Occasionally a mass in the region of the pancreas will be palpable.
• Jaundice or yellowing of the skin and mucous membranes may be the first clinical sign noted. In the case of pancreatic exocrine neoplasia this is usually associated with the tumor obstructing the outflow of bile.
• There are no specific laboratory abnormalities for pancreatic cancer. The white blood cell count may reflect inflammation. The red blood cell count and total protein may suggest dehydration. Elevations in liver enzymes and bile products in the blood would confirm the bile obstruction.
• Abdominal X-rays may confirm the presence of a mass in the right upper quadrant. A mass may displace other organs in that area such as the duodenum, stomach and liver. Inflammation in the vicinity of the pancreatic tumor can produce a non-bacterial accumulation of fluid, which tends to decrease the detail of the X-ray, creating a so-called “ground glass” appearance to the image.
• Abdominal ultrasound is sensitive in detecting not only a mass within the pancreas, but the presence of metastasis to local lymph nodes or other organs such as the spleen or liver. The effect of a pancreatic tumor on the bile outflow tract can also be appreciated.
• Ultrasound-guided fine needle aspiration of the tumor is a minimally invasive technique that in many cases can produce a diagnosis without the need for surgery. Under sedation or general anesthesia, the mass is located using ultrasound. If it can be isolated and deemed to be safe relative to other important and often vascular structures nearby, a needle is guided into its core and cells aspirated to be evaluated by a pathologist.
• In some cases where there is an effusion, a sample of fluid from the abdomen may contain neoplastic cells originating from the pancreatic tumor.
• When ultrasound is not available, diagnosis may be made at the time of surgery. Pancreatic exocrine neoplasia can grossly resemble some variants of acute or chronic pancreatitis and so definitive diagnosis should be made by biopsy and histopathologic evaluation. Fresh frozen samples taken at the time of surgery may be evaluated and a diagnosis obtained in about twenty minutes in certain referral and university hospitals.

In-depth Information on Treatment

• Treatment for exocrine pancreatic neoplasia is almost always unrewarding using either a medical or a surgical approach. The most common reason for this negative outlook is that the cancer has usually spread by the time the veterinarian has made the diagnosis.
• The tumor does not respond well to chemotherapy and therefore this approach alone has no merit.
• In most cases, at the time of surgery, the mass is large, invasive and has spread to other abdominal organs. The pancreas is an important organ in the body. Not only does it have a role in the digestion of food but it is also responsible for producing insulin and regulating levels of blood glucose (sugar). If the pancreas were completely removed, the pet would be a diabetic and would need enzyme supplementation to assist with digestion. He would also need the stomach rerouted to the small intestine to allow outflow of food from the stomach and require rerouting of bile from the gall bladder to the small intestine. When all of these procedures are considered, together with the poor outlook and rapid spread for this tumor, it is not surprising that, sadly, in most cases, the most humane option is euthanasia, once the diagnosis has been made.
• In the rare case that the tumor has not spread and can be removed, tumor removal would often be followed by placement of a jejunal feeding tube, to allow your pet to receive nutrition directly into the small intestine at a level below the pancreas.
• After pancreatic surgery food is not offered by mouth for 2 to 5 days. Hydration and electrolytes are maintained by intravenous fluids. Nutrition will be provided either intravenously or via a feeding tube.
• Small amounts of low fat bland food such as scrambled egg or boiled chicken and boiled rice may be offered after a few days. If vomiting does not occur then your pet may be discharged from the veterinary hospital.

Follow-up Care for Dogs with Pancreatic Exocrine Neoplasia

Antibiotics may be used in some cases of pancreatic surgery depending on the findings at the time of the procedure. These medications may continue when your dog comes home. You will need to offer your dog small meals and water. Do not be tempted to offer too much food, too many treats or the opportunity to gorge on fluids.

If a feeding tube has been used, feeding may still be supplemented by use of a liquid diet that is syringed directly into the intestinal tract. Your veterinarian will go over the dietary protocol for the tube and care of the stoma, the opening where the tube exits the skin on the side of the abdomen. A feeding tube will stay in for at least five days following surgery, whether your pet is eating or not. If your pet is eating by mouth problems, the feeding tube may be pulled after this time. This procedure would be performed by your veterinarian.

Check the surgical incision for swelling redness or discharge. The stitches or staples will need to be removed in 10 to 14 days.

There is no preventative action for exocrine tumors of the pancreas in cats and dogs. Fortunately these tumors are rare and therefore it is important to bear in mind that the likelihood of such a tumor being the reason for your pet’s abdominal discomfort or vomiting is usually slim.

Benign tumors of the pancreas can occur but they are usually asymptomatic and an incidental finding at the time of an exploratory surgery, more often than not for reasons other than suspected pancreatic disease.

The prognosis for malignant pancreatic exocrine tumors is extremely poor.