Insulinoma in Dogs

Overview of Canine Insulinoma

An insulinoma is a malignant tumor of the pancreas that secretes excessive amounts of insulin leading to hypoglycemia (low blood sugar concentration). Insulinomas usually occur in middle-aged to older dogs, usually eight to twelve years of age. They are very rare in cats and there is no apparent gender predilection.

Insulinomas can occur in any breed of dog with mixed breed dogs most commonly affected. Among purebred dogs, Irish setters, German shepherds, boxers, golden retrievers, poodles, and Labrador retrievers have a higher incidence. Medium to large-sized breeds of dogs are most commonly affected.

The excessive secretion of insulin by these tumors causes hypoglycemia and clinical symptoms of hypoglycemia.

What to Watch For

Diagnosis of Insulinoma in Dogs

Diagnostic tests are needed to identify insulinoma and exclude other diseases. Your veterinarian may recommend the following:

Treatment of Insulinoma in Dogs

Treatment for acute insulinoma may include the following:

Long-term treatment:

Home Care and Prevention for Insulinoma

Administer as directed any medications prescribed by your veterinarian and follow any special dietary recommendations. Watch your dog carefully for signs of hypoglycemia and administer corn syrup orally if you see signs of hypoglycemia, such as seizures, weakness or muscle tremors.

Observe your dog’s general activity level, appetite and attitude. Watch for recurrence of clinical symptoms of hypoglycemia that may indicate recurrence of the tumor. Feed frequent small meals of a high carbohydrate diet to maintain adequate blood sugar concentration.

Schedule regular follow-up visits with your veterinarian to monitor your dog’s progress and promptly identify any recurrence of hypoglycemia and insulinoma.

Keep your dog’s exercise and activity level relatively constant. Avoid intensive exercise or provide high carbohydrate snacks before exercise.

The cause of insulinomas is unknown, and consequently there is no way to prevent development. You can prevent a hypoglycemic crisis by following the dietary, exercise, and medical recommendations of your veterinarian.

Information In-depth for Insulinoma in Dogs

The pancreas contains collections of cells called islets of Langerhans. Normal islets contain four cell types: alpha, beta, delta, and F cells. Each of these cell types produces a specific hormone. Beta cells produce insulin. Excessive amounts of insulin are released into the bloodstream when a malignant tumor (insulinoma) develops from the beta cells. In normal animals, insulin works with other hormones to maintain blood sugar concentration in the normal range (approximately 70 to 100 milligrams per deciliters of blood). Excessive secretion of insulin by the beta cell tumor (insulinoma) causes the blood sugar concentration to fall below the normal range (hypoglycemia) with several different possible symptoms including:

Most dogs with insulinomas display some of the symptoms listed above, but these symptoms tend to be intermittent and physical examination at the veterinarian’s office usually is unremarkable. Other medical problems can lead to symptoms similar to those encountered in insulinoma. It is important to exclude these conditions before establishing a definitive diagnosis:

Veterinary care should include diagnostic tests and subsequent treatment recommendations.

Diagnosis In-depth of Insulinoma in Dogs

Diagnostic tests are needed to recognize insulinoma and exclude other diseases. Tests may include:

Treatment In-depth for Dogs with Insulinoma

Treatment of acute insulinoma must be individualized based on the severity of your dog’s condition and other factors that must be analyzed by your veterinarian. Treatments may include surgery, medical management, or a combination of both.

Surgical removal

Surgery is usually the first approach to management and allows the possibility of cure for a dog with a single, easily removable tumor. Unfortunately, the tumor has usually spread to other abdominal sites, often the liver and regional lymph nodes, by the time a diagnosis is made, and surgery is only a temporary help. If the entire tumor is not removable, or if there has been spread to other organs, removal of as much abnormal tissue as possible usually results in remission of the symptoms of hypoglycemia and improves the response to medical therapy.

Medical therapy

Long-term therapy

Long-term medical therapy is instituted if surgery is declined, the tumor cannot be completely removed or the tumor has spread to the liver and regional lymph nodes. Also, if a large amount of the tumor was removed surgically and clinical symptoms were controlled initially but have now reappeared, long-term therapy should be initiated, consisting of:

Follow-up Care for Dogs with Insulinoma

Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be crucial. Follow-up for insulinoma often includes the following: