Insulinoma in Dogs

Insulinoma is a condition that involves a tumor on the pancreas, which will cause a drop in the blood sugar and an increase in the insulin production. The tumor can be removed through surgery, but most commonly, it will grow back and the condition can easily metastasize.

Causes of Insulinoma

Insulinoma is caused by the presence of a tumor on the pancreas, which will cause low blood sugar and increased levels of insulin. The causes of the tumor growth are not known, however, older dogs are more likely to develop these tumors.

Symptoms of Insulinoma

The symptoms of insulinoma will be similar to the symptoms of hypoglycemia. Watch out for symptoms, such as:

  • Lethargy
  • General state of weakness
  • Increased sleep hours
  • Pale gums
  • Lack of appetite
  • Weak pulse and slower heart rate
  • Fainting or sudden collapse

If you administer some sugar, maple syrup or honey to your pet, his condition can improve, however, the pancreas tumor will cause a constant drop in the blood glucose, so your pet will experience a relapse shortly.

Diagnosing Insulinoma in Dogs

The diagnosis can be made based on the symptoms and by performing a few tests. The symptoms will point to a low blood sugar and the vet will perform some blood tests to see how severe the problem is and find the possible causes of hypoglycemia. If the vet suspects a pancreatic tumor, he will perform some chest x-rays to establish the size of the tumor and to see whether surgery is an option. Additional ultrasounds may also be performed.

Treatment Options for Dog Insulinoma

While your vet will typically attempt to surgically remove the tumor on the pancreas, this is not always recommended. If the tumor is too large and it has extended to other organs (e.g. the liver), the surgery is an impractical solution. In most cases, the tumor will grow back after the surgery (typically within 8 months) and will metastasize to the liver. Less than 5% of dogs will not have a new tumor after insulinoma surgery. Surgery may also be dangerous for dogs that have a very low blood sugar, so the dog’s blood sugar should be stabilized prior to surgery. Intravenous dextrose should be administered during the surgery. Medication therapy may also be available and will aim at reducing the insulin levels and increasing the blood sugar. The dog should receive more frequent meals, which will keep the blood sugar at a constant level.

Prognosis for Dogs with Insulinoma

The prognosis for dogs with insulinoma is poor. Even if surgery is possible, the tumor can grow back and this usually happens in 8 to 12 months after the initial surgery. If surgery is possible and is used in conjunction with medication treatment, the dog can survive for up to 2 years. If surgery is not possible and the dog receives only medication, he may die within 6 months.