Pancreatic Cancer in Dogs

The good news is that pancreatic cancer in dogs is quite rare. The bad news is that when it does occur, it is usually malignant and aggressive. As with all cancers in dogs’ early detection is key to improving their chance of survival. Therefore, being familiar with your furry friend’s normal behavior and eating habits could be beneficial in recognizing tell-tale symptoms of various illnesses, including cancers.

Dog Pancreas’ Role In Health

As in humans, the pancreas plays a vital role in a dog’s life. Lying on the right side of the abdomen next to the stomach, it’s really two glands in one: a digestive gland and a hormone-producing gland. The enzymes produced by the pancreas assist in the digestion of food. The pancreas is also the producer of the body’s insulin and glucagon, which is essential to regulating blood sugar levels in a pup.

What is a pancreatic tumor? Are they always cancerous?

A pancreatic tumor can result when there is an abnormal production and replication of cells within the pancreas. The pancreas comprises two types of cells – exocrine (gland and ducts) and endocrine cells (hormone production) – and tumors may originate from either of these two types of cells so broadly tumors fit into one of those two categories. Tumors can be benign or malignant and it should be noted pancreatic tumor symptoms can be similar to pancreatitis.

Types of Pancreatic Cancer in Dogs & Symptoms

Pancreatic tumors form in the two types of cells in the pancreas (exocrine and endocrine), but there are different types of cancer that can occur. The two most common, insulinomas and adenocarcinoma have very different symptoms, while the less common, gastrinomas and glucagonomas are still dangerous for your dog.

Symptoms of Pancreatic Cancer in Dogs

Insulinoma – dogs who have an insulinoma tumor will produce an excessive amount of insulin, reducing blood sugar levels.
Adenocarcinoma – cancer that forms directly in the dogs pancreatic glands, can have symptoms that mimic a pancreatitis (inflammation of the pancreas).
Gastrinomas – unregulated gastrin secretion that increases a dog’s gastric acid production, resulting in ulcerations of the small intestine.
Glucagonomas – occurs in the part of the gland that produces the hormone glucagon, much less common in dogs.

Insulinoma Cancer Symptoms

The most common type of malignant pancreatic tumor, insulinoma tumors’ impact on your dog’s blood sugars will, unfortunately, have a notable effect on your dog’s health and behavior. Blood sugar is one of the ways your dog naturally regulates its energy usage, so when it’s out of whack your dog may have difficulty doing some basic activities. Symptoms to insulinoma tumors include:

Lack of energy and less interest in activities they usually enjoy
Fainting when hungry
Reduced coordination, wobbling when walking
Confusion
Muscle twitching
Seizures

Adenocarcinoma Symptoms

Unlike insulinoma tumors, adenocarcinomas can often produce “vague” symptoms, which means cancer may not be diagnosed until the disease has progressed. Also, the symptoms can mimic those of pancreatitis, which is an inflammation of the pancreas, making it even more difficult to diagnose. These symptoms include:

A reduced appetite for food and water
Weight loss
Vomiting
Lack of energy
Abdominal pain, sensitivity, or distention
Weight loss
Jaundice

Diagnosis of Pancreatic Cancer In Your Dog

The diagnostic techniques consist of positive contrast upper gastrointestinal x-rays, flow cytometry, and ultrasound.

X-rays (radiographs) – may reveal delayed gastric emptying and compression or invasion of the duodenum. In ascites, there is an abnormal growth of cells that may be revealed on cytologic evaluation.
Flow cytometry (cell analysis) – is useful in differentiating between malignant and benign abdominal effusions, requiring tissue or blood.
Ultrasonography – is useful in localization of the primary tumor, documentation, aspiration of fluid, and metastasis to liver and regional lymph nodes.

If not detected early, insulinomas and adenocarcinomas can spread, as is common with this form of cancer, and your dog may have difficulty breathing or may appear lame.

Some of the symptoms listed above are also signs of other illnesses. The sooner you can receive a diagnosis and start treatment, the better the chances of recovery.

Diagnosing pancreatic tumors can be challenging for vets. Not only is pancreatic cancer in dogs relatively rare, but the symptoms may come and go. Further, the pancreas is so tiny that imaging has its limitations. Sometimes the veterinarian may opt to diagnose through surgery and examination (via flow cytometry) of the pancreas. However, this may not be an optimal solution and treatment may be started without visualization of the tumor.

Treatment for Canine Pancreatic Cancer

With pancreatic cancer in dogs, surgery is generally the most effective to diagnose, stage, and treat cancer. These surgeries include:

Pancreatectomy – complete removal of the pancreas or a
Pancreaticoduodenectomy – the head of the pancreas, the entire duodenum, a portion of the jejunum, the distal third of the stomach, and the lower half of the common bile duct are removed
Palliative gastrointestinal bypasses – allow the passage of food into the intestine (temporary option if there is bowel obstruction)

During surgery, other abdominal structures can be assessed for the spread of cancer. Additionally, an effort may be made to stabilize blood glucose through diet and drugs.

If surgery is not an option, your Veterinarian may try to manage your dog’s low blood sugar symptoms. This may be done through a modified diet and feeding plan combined with medications to suppress insulin secretion.

Although surgery can be effective in adenocarcinomas, there is a great risk of life-threatening complications. Chemotherapy is generally not effective in the treatment of adenocarcinomas in dogs.

Cause of Pancreatic Cancer in Dogs

As with most cancers, it’s hard to pinpoint an exact cause. The statistics do demonstrate that certain breeds are more likely to develop this type of cancer.

Larger breed dogs such as Boxers, German Shepherds, Irish Setters, and Golden Retrievers have a greater tendency to develop pancreatic cancer. Additionally, a dog’s age can be a factor, with middle-aged and older dogs more prone to pancreatic cancer.

Canine Pancreatic Cancer Prognosis

As noted, pancreatic tumors are often malignant, meaning that there is a high probability that cancer has spread before it’s been detected. Unfortunately, this can make for a poor prognosis for dogs with pancreatic cancer. If the type of tumor has been identified and your vet completed staging tests, they may be able to give you a prognosis.

Often the prognosis for a dog suffering from pancreatic cancer is six months to a year, however, that can be different depending on how early it was diagnosed. Sometimes, depending on severity and treatment plan it could be as long as two years. Generally, survival rates are only described as fair. In many cases, cancer moves to the lymph nodes, liver, and small intestine after starting in the pancreas. If this happens, it can dramatically reduce life expectancy.