What is an insulinoma?
An insulinoma is a tumor of the pancreas, this glandular organ located near the first part of the small intestine. It is the most common pancreatic tumor in dogs, just before adenocarcinoma.
It is more precisely a tumor that affects the endocrine cells of the pancreas, and in particular the beta cells that secrete insulin, one of the hormones responsible for regulating blood sugar (level of blood glucose).
Insulinoma is a cancer that can metastasize quickly, i.e. spread to other parts of the animal's body, especially to nearby lymph nodes or the liver.
Certain breeds of dogs seem predisposed to this type of tumor such as the Poodle, the German Shepherd, the Labrador or even the Golden Retriever.
What are the symptoms of insulinoma in dogs?
An insulinoma generally causes an excessive secretion of insulin, which is responsible for a drop in blood sugar levels. This hypoglycaemia then leads to fatigue and convulsive episodes which, as the disease progresses, tend to increase in frequency.
When metastases are present, they are likely to cause fluid to accumulate in the abdomen, which leads to abdominal distention.
How is an insulinoma diagnosed?
These tumors are usually diagnosed through blood tests and an ultrasound of the pancreas area.
In case of insulinoma, blood tests usually show low blood sugar (glucose) and normal to high insulin levels.But, even if abnormalities are found, they are often too general to indicate the presence of cancer, so blood tests are often helpful but inconclusive.
What treatment for an insulinoma?
Surgery to remove part of the pancreas (partial pancreatectomy) may be considered. And while surgery can be helpful, any pancreatic surgery is tricky because it risks causing pancreatitis, a potentially fatal post-operative complication.
When surgery is not possible or has not removed all the tumors (if there are metastases), the symptoms of hypoglycemia can be managed by the splitting of the dog's meals into 3 to 4 meals a day and by medical treatment based on the injection of glucose, corticosteroids or other molecules which make it possible to regulate the secretion of insulin.
Alas, despite treatment, the prognosis for your pet is generally poor in the short term as these tumors tend to have already spread by the time they are diagnosed.