Pancreatic Cancer In Dogs

The pancreas is an organ you may not be familiar with, but it plays an important role in your health and your dog’s health, too. Located in the abdomen, the pancreas produces enzymes that help the digestive process. It also produces insulin, a hormone that helps control a dog’s glucose (blood sugar) level as well as his or her ability to convert glucose to energy.

Two distinct types of tumors can originate in the pancreas. Insulinomas are tumors that arise from the beta cells of the pancreas which then causes the organ to secrete too much insulin, while pancreatic adenocarcinoma tumors are a type of cancer that originates from the glandular tissue of this organ. Both are serious threats to a dog’s health. Fortunately, both types of pancreatic tumors in dogs are rare, with fewer than 1% of dogs developing them. Dogs stricken with pancreatic cancer typically are older.

Since pancreatic adenocarcinomas and insulinomas originate from different cell types, symptoms to watch for differ greatly, as do treatment options. Thus, they are addressed separately below.

Symptoms of Pancreatic Cancer in Dogs: Adenocarcinoma

Both male and female dogs can develop this type of pancreatic cancer. Breed does not appear to be a factor, either. As with many types of cancer, early detection is critical, so paying attention to symptoms is paramount. A dog stricken with pancreatic adenocarcinoma may show a wide range of signs. These include:

• Anorexia (not eating or eating very little)
• Weight loss
• Vomiting
• Abdominal pain
• A bloated/pot belly appearance (from fluid building up)
• Occasional diarrhea
• Lethargic behavior

These symptoms can also present with other diseases, including other types of cancer, so it’s important to get an accurate diagnosis from your veterinarian.

Diagnosing Adenocarcinomas

If your dog is experiencing symptoms consistent with those mentioned, a veterinarian typically will perform a series of procedures to determine whether there is indeed a tumor on the dog’s pancreas or whether something else is causing the issue(s). Diagnostics typically would include:

• A blood draw to get a complete blood count (CBC) and blood chemistry profile. With a chemistry profile there may be an elevation in liver enzymes or pancreatic enzymes (such as lipase or amylase)
• Urinalysis to detect abnormalities and further assess kidney function, in conjunction with the chemistry profile
• An abdominal ultrasound to get a visual of the area and to see if the cancer has spread to other abdominal organs
• Possibly an abdominal CT scan for a more detailed look, especially to prepare for potential surgery
• 3-view chest X-rays to determine whether cancer has spread

Treatment and Prognosis

Adenocarcinoma is a very aggressive canine pancreatic cancer and the prognosis is often poor. It tends to progress quickly with metastasis (spread) occurring in many cases. Spread to the regional lymph nodes, liver, lungs and on rare occasions the spleen often occurs — at times, even before diagnosis. It can also spread into the peritoneum in which cancer cells reside on the external layers of other organs in the abdomen. This condition is called carcinomatosis.

Treatment for pancreatic cancer in dogs depends largely on whether metastasis has taken place. Sometimes a tumor can be surgically removed, but sometimes it cannot even without metastasis. Chemotherapy is another option which may or may not help for several months. Chemo can be administered intravenously or orally, including via a pill called Palladia. However, some of these tumors don’t respond to chemo. Radiation therapy for pancreatic cancer is rarely recommended.

Symptoms of Pancreatic Insulinoma

As mentioned earlier, insulinomas are another type of (cancerous tissue growth). They originate from the beta cells in parts of the pancreas known as the islets of Langerhans. Since these tumors make more insulin than the body can use, this results in a dog having a very low blood sugar, just like when a diabetic person injects too much insulin by accident. When a dog’s blood sugar plummets below its standard range, he or she is considered hypoglycemic. Signs of hypoglycemia include:

• Acting mentally dull or confused
• Weakness
• Weight loss
• Excessive thirst and urination
• Dehydration
• Vomiting
• Shaking or jittery or muscle fasciculations
• Collapse
• Seizures — Seizures are particularly noteworthy. The brain needs a certain amount of glucose to function properly, and a seizure can be the result of low blood sugar. If your dog is having a seizure, take him or her to the nearest clinic for appropriate emergency care.

Diagnosing Pancreatic Insulinomas

As symptoms associated with pancreatic insulinomas can also be symptoms of other diseases and types of cancer, your veterinarian can run a series of tests to help make an informed diagnosis. These typically would include:

• Bloodwork to get a complete blood count (CBC) and a blood chemistry profile
• Urinalysis to check for abnormalities
• Possibly serial blood sugars as well as insulin levels
• Three-view chest X-rays and perhaps an abdominal X-ray
• Possibly a CT scan of the abdomen
• Aspiration and/or biopsy, so samples can be analyzed by a veterinary pathologist to obtain a definitive diagnosis.

The bloodwork could reveal elevated levels of pancreatic enzymes, such as lipase or amylase, or elevated levels of liver enzymes. An abdominal X-ray or ultrasound might reveal a mass, but the image alone doesn’t tell a veterinarian whether that mass is benign and perhaps just an abscess, or perhaps something more serious. Completing the diagnosis might require aspirating the mass (using a fine needle to take a sample) or even performing an abdominal exploratory surgical procedure to biopsy (or remove) the tumor. The veterinarian likely would want to rule out pancreatic adenocarcinoma or lymphoma, which is also rare, to diagnose the tumor as an insulinoma.  In only very rare, serious cases, pancreatitis could also cause these same clinical signs.

Treatment and Prognosis

There are multiple options for treating pancreatic insulinomas. Factors that help determine which options are most viable include the extent to which the tumor has progressed, the exact location, the dog’s overall health and others.

Surgery

Surgical removal of an insulinoma is sometimes possible — but not always. The majority of insulinomas occur in the right lobe of the pancreas, so surgeons sometimes remove the right lobe if an actual mass cannot be found, in the hopes of removing the tumor. Post-surgery, periodic checks of glucose would be recommended. Sometimes blood sugar levels will normalize; other times they won’t. These typically correspond to the amount of cancer still present in the patient.

Chemotherapy, Other Drugs and Diet

Insulinomas often metastasize to the lymph nodes, liver and lungs. In such circumstances, surgery is not viable. Chemotherapy with a tyrosine kinase inhibitor or other medications can be tried, including diazoxide, somatostatin, or glucagon. The effects of insulinomas can also sometimes be controlled for a short time with steroids and small, frequent meals consisting of a high-protein diet with only complex carbohydrates and no simple sugars.

In circumstances that don’t involve surgical removal, the prognosis depends on the extent of the insulinoma’s impact and the ability to control the dog’s blood sugar. The prognosis may be just weeks to a few months; for dogs with aggressive care (surgery, chemotherapy, diet change, etc.), it might be several months to a year or so. Consultation with a veterinary oncologist is recommended.

PetCure Oncology and Pancreatic Cancer Treatment

PetCure Oncology offers a wide range of treatment options for many different types of cancer, including pancreatic cancer in dogs. We are known for our use of (SRS/SRT) — an advanced form of radiation therapy — for cancers that indicate such treatment. However, our true specialty is compassionate care for all of our patients. We’re here because we want to provide your pet the best quality of life while extending your time together as long as possible. For more information about our treatments and our mission, find a location near you and contact us today.

The contents of this article were provided in part by Dr. Renee Alsarraf, DVM, DACVIM (Oncology), a board-certified veterinary medical oncologist and member of PetCure Radiation Oncology Specialists (PROS).