Pancreatic Cancer and Insulinoma in Dogs

Insulinoma in Dogs

An insulinoma releases too much insulin, so blood sugar drops even when a dog hasn't eaten.^1,9 Almost all insulinomas in dogs are cancerous, and about half have already spread to nearby lymph nodes or the liver when found.^3,1,9 It usually affects middle-aged and older dogs, most often around 9 to 10 years of age, and medium to large breeds.^3,1,8 Breeds with higher odds in UK data include Dogues de Bordeaux, German Pointers, Flat-coated Retrievers, Boxers and West Highland White Terriers.⁸

Signs of insulinoma

• Weakness, especially in the back legs, or tiring after exercise^2,4
• Muscle twitching, wobbliness or confusion^2,1
• Restlessness or changes in temperament²
• Collapse or seizures^1,4

Episodes come and go, often after exercise, fasting, excitement or a meal, and dogs usually seem normal in between. They tend to become more frequent and last longer.^9,1 Repeated severe low sugar can cause lasting brain damage.¹

Diagnosis

Vets look for low blood sugar together with an insulin level that is normal or high when it should be low. They also rule out other causes such as Addison's disease and liver disease.^3,9 Contrast CT finds most primary tumors, while ultrasound misses many.^3,1

Treatment

• Surgery to remove the tumor and part of the pancreas gives the longest survival. Enlarged lymph nodes and liver spread are removed or reduced at the same time.^9,1,3 Keyhole surgery is possible for some tumors.¹⁰
• After surgery, about 1 in 10 dogs develops pancreatitis, some have low sugar that persists (which suggests tumor remains), and some develop temporary or lasting diabetes.^3,5
• Medical treatment includes a medicine that blocks insulin release, steroids, and in some cases chemotherapy or a targeted kinase-inhibitor tablet, used as your vet directs.^1,3,11
• Feeding: 4 to 6 small meals a day of a high-protein food with complex carbohydrates, no sugary treats, and short leash walks instead of hard exercise.^9,1,3

Outlook

After surgery to remove an insulinoma, most dogs live about 1 to 2 years, and longer when the tumor hasn't spread.^4,5,3 With medicines and diet alone, survival is usually several months to under a year, though newer targeted treatments look promising in early studies.^3,4,11 Low blood sugar usually returns eventually.^3,9

Pancreatic Adenocarcinoma

Exocrine pancreatic tumors come from the cells that make digestive enzymes. Benign adenomas are rare and usually cause no signs. Adenocarcinoma is the most common malignant type.⁷ Exocrine pancreatic tumors make up less than 0.5% of cancers in pets, and affected dogs average about 9 to 10 years old.¹²

Signs

• Poor appetite and lethargy^6,12
• Vomiting and belly pain, which can look like pancreatitis^6,7
• Yellow skin, gums or eyes (jaundice) if the tumor blocks the bile duct⁷
• Lameness, bone pain or breathing trouble if it has spread⁷

Pancreatitis often occurs alongside the tumor and can make it harder to diagnose. See pancreatitis in dogs.¹²

Treatment and outlook

Pancreatic adenocarcinoma is usually found late, after it has spread, and most dogs live only days to a few months. Surgery helps only in rare cases caught early.^6,7 Chemotherapy and radiation have had "little success."⁷ One dog lived 445 days after surgery and follow-up tablets, which its authors called the longest survival reported.¹² For many dogs, comfort care focused on pain relief and nausea control is the kindest option. See quality of life and when to say goodbye.¹³

Frequently Asked Questions

What are the signs of pancreatic cancer in dogs?

Insulinoma causes episodes of weakness, wobbliness, confusion, collapse or seizures. Pancreatic adenocarcinoma causes poor appetite, vomiting, belly pain and sometimes jaundice.

How long can a dog live with pancreatic cancer?

With insulinoma, often 1 to 2 years after surgery. With pancreatic adenocarcinoma, usually only days to a few months.

Does pancreatic cancer cause a quick death in dogs?

Pancreatic adenocarcinoma is usually advanced when found. Insulinoma progresses more slowly, but a severe low-sugar crisis is an emergency.

What is insulinoma in dogs?

A tumor of the pancreas that releases too much insulin, causing low blood sugar.

What should I feed a dog with insulinoma?

Several small meals a day of a high-protein food with complex carbohydrates, and no sugary treats.