Knowing that pancreatic cancer is less common than many other forms of canine cancer is cold comfort if your dog has been diagnosed with the disease. The two main forms of malignancy affecting this hormone and enzyme-generating gland have entirely different signs and symptoms, treatments and possible outcomes, although both tend to affect middle-aged dogs. If you find yourself faced with a tough decision after terrible news, consider asking your vet whether palliative care might be a realistic option.
What the Pancreas Does
The pancreas, a glandular organ near the liver and stomach, contains two groups of cells, each with a vitally important function. Endocrine cells produce hormones, including insulin, which regulate blood sugar, while exocrine cells produce enzymes, which help digest food. Not all pancreatic tumors are malignant but the two main types that have different clinical names depending upon which cell groups they target, along with different signs, symptoms, treatments and possible outcomes.
Insulinomas Can Mimic Diabetes
Normally, insulin production is tightly controlled by the pancreas to ensure that blood sugar levels remain stable and constant. Cancers that affect insulin-secreting cells, called pancreatic insulinomas, knock out the gland's ability to regulate insulin production, thereby creating symptoms much like progressively severe, untreated diabetes. Overproduction of insulin leads to hypoglycemia, or low blood sugar. Affected dogs typically seem lethargic and confused. They may develop tremors and walk with an unsteady gait. Seizures or convulsions are common. Since many other conditions can cause similar symptoms, the vet might use ultrasound to check for a pancreatic mass. According to veterinarian Wendy Brooks, educational director for VeterinaryPartner.com, surgery to remove the tumor and part of the pancreas is delicate but if the disease hasn't spread, outcomes are encouraging, especially when combined with dietary restrictions and appropriate medications.
Adenocarcinomas Spread Aggressively
Pancreatic adenocarcinomas, cancers affecting enzyme-secreting cells, are more common -- and much more aggressive -- than insulinomas. Symptoms include abdominal pain, vomiting and weight loss. Usually, a vet can feel a mass in an affected dog's abdomen. Since these tumors often block the bile duct, jaundice is another common sign. When tumors press on veins, the resulting buildup of fluid can cause abdominal swelling. In addition, simultaneous leakage of digestive enzymes from the pancreas breaks down and destroys surrounding tissues, increasing the dog's pain. By the time the cancer is diagnosed through surgical biopsy, it has typically spread to the dog's abdominal lining, liver and lymph nodes. By then, it's too advanced to respond to treatment so the only thing a vet can do is try to manage the dog's pain, says the National Canine Cancer Foundation.
Some Breeds Are More Susceptible
Pancreatic cancer usually strikes older dogs aged 9 to 10, although younger mature dogs can contract it too, and some breeds appear more susceptible than others, says the Veterinary Society of Surgical Oncology. Irish setters, golden retrievers, German shepherds, boxers and standard poodles are at increased risk for insulinomas, while Labrador retrievers, boxers, cocker spaniels and Airedale terriers are predisposed to adenocarcinomas.
If your dog is diagnosed with adenocarcinoma and there's no hope for cure, of course, you don't want to see him suffer. But bioethicist Jessica Pierce, author of "The Last Walk: Reflections on Our Pets at the End of Their Lives," wants you to know that you don't always have to rush into a decision about euthanasia. In an essay published in "The New York Times" in September 2012, Pierce wrote movingly about her personal turmoil when confronted with the progressive and incurable illness of her beloved dog Ody. With effective pain management, terminally ill dogs, like their human counterparts, can continue to enjoy life, as Ody did, until nature takes its course or all possibility of any further enjoyment is gone, she wrote. VCA Animal Hospitals agrees, urging people who wish to provide palliative care for their pets to talk to their vets about developing a suitable plan.