Progression of Insulinoma in Dogs

Insulinoma is a rare and deadly condition in dogs associated with the growth of a pancreatic tumor. It progresses through three clinical stages, which chart the scope of the illness. While many cases ultimately prove fatal, some canine patients recover completely after treatment and others live for years.

Insulinoma starts as a single bump on your dog's pancreas. The growths are small by tumor standards, often measuring only a few millimeters in diameter. During stage I of the disease, the malignant growth only occurs on the pancreas and has not spread to the lymph nodes. Pancreatic tumors release excessive amounts of insulin into the bloodstream, which produces severe hypoglycemia. Dogs may appear exhausted, adopt strange behavior and suffer seizures after this change in body chemistry. Canines diagnosed during stage I are prime candidates for surgical treatment, which may lead to a cure.

Malignant cells eventually spread from the pancreas and infiltrate the surrounding lymph nodes. Insulinoma is considered stage II once the disease metastasizes. Between 30 and 50 percent of cases are in this phase by the time they are surgically diagnosed, according to the Veterinary Society of Surgical Oncology. Since pancreatic tumors don't always show up on X-rays and other scans, veterinarians may not discover the scope of the disease until the animal is on the operating table. Unfortunately, even a surgical examination may not identify microscopic malignant growths in other tissues in the dog's body. Insulinoma is classified as stage III once cancerous cells migrate from the lymph nodes to other vital organs, such as the liver or stomach.

Dogs suffering from stage I insulinoma have the potential to be cured through surgery, although complications after surgery and recurrence of the disease are common. Since surgery rarely produces positive results in more advanced cases, vets turn to a long-term medicinal management strategy instead. This type of treatment accompanies a change in diet, with the canine patient eating many small meals often throughout the day to maintain blood sugar levels. Vets may also prescribe prednisolone and other medicine to help manage the problem as well.

While some lucky dogs make a full recovery after surgical treatment, many cases eventually result in the patient's death. That doesn't mean you need to say goodbye to your pup when you receive the diagnosis. Dogs receiving medicinal therapy for the disease often live for a year or more. In cases where blood sugar levels are stable, dogs may survive with relatively few symptoms for more than three years, according to Davies Veterinary Specialists. Since many dogs are more than 10 years old when they develop insulinoma, some owners opt out of surgical treatment and focus on easing their pet's discomfort during his final months.