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Insulinoma (Pancreatic Islet Cell Tumor) in Dogs

Occurrence: rarer
Location of illness: Abdomen/pelvis

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

An insulinoma is a tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. of the beta cells in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation. of dogs that uncontrollably produces insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus., leading to hypoglycemiaHypoglycemia is a condition in which blood sugar levels fall below the normal range. Symptoms may include tremors, sweating, Hunger, confusion, and in severe cases, loss of consciousness., i.e., low blood sugar.

The most important facts at a glance

InsulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. are rare but serious Tumors in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation. of dogs that arise from the insulin-producing beta cells of the islets of Langerhans. They are usually malignantMalignant means "cancerous" and is used to describe tumors or neoplasms that grow invasively and have the ability to metastasize. Malignant tumors can cause serious health problems in dogs and cats. and can lead to dangerously low blood sugar levels. The exact cause is unclear, but genetic and environmental factors, as well as certain breeds such as Boxers and German Shepherds, may play a role. A high-carbohydrate diet could theoretically increase the risk.

Symptoms include weakness, weight loss, neurological problems, and sometimes Convulsions. DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is made by clinical examination, blood tests to measure blood sugar, and imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow.. A high insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. concentration in the blood with low blood sugar indicates an insulinoma. Treatment consists of surgical removal, if possible, and drug therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. to control insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. levels. A low-carbohydrate diet can also help.

The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on many factors, such as the possibility of complete tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. removal and the presence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body.. Early detection is crucial for a better prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop.. Since the causes are unclear, there are no specific preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. measures. However, a balanced diet and regular veterinary check-ups can promote general health. Research focuses on the development and treatment of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment., with new diagnostic and therapeutic approaches being developed.

Causes

Insulinomas are rare but serious tumors that arise from the insulin-producing beta cells of the islets of Langerhans in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation.. These tumors are usually malignant and can grow locally invasively or metastasize, i.e., spread to other parts of the body. The excessive production of insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. by the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. causes an abnormally low blood sugar level, which is dangerous for the body.

The exact cause of insulinoma development is not fully understood. However, it is believed that genetic and environmental factors may play a role. Certain breeds appear to be more susceptible, including Boxers, Fox Terriers, and German Shepherds, which may indicate a genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases..

Another possible factor for the development of an insulinoma could be the dog’s diet and lifestyle. A diet high in carbohydrates and sugar could theoretically increase the risk, although this has not yet been extensively studied. Similarly, chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. inflammatory conditions in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation. could increase the risk of developing tumors.

Symptoms

Very common symptoms:

Common symptoms:

Rare symptoms:

The symptoms of an insulinoma in dogs are mainly due to the hypoglycemiaHypoglycemia is a condition in which blood sugar levels fall below the normal range. Symptoms may include tremors, sweating, Hunger, confusion, and in severe cases, loss of consciousness. caused by excessive insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. production. Typical signs include weakness, tremors, confusion, coordination disorders, and in severe cases, convulsions. The dog may also collapse due to low blood sugar.

Other symptoms may include behavioral changes, such as increased irritability or ApathyApathy refers to a state of indifference and reduced interest or lack of emotional involvement in activities or events that would normally arouse interest., as well as weight loss despite normal or increased appetite. In some cases, gastrointestinalGastrointestinal refers to the gastrointestinal tract, a system that extends from the oral cavity to the anus and is responsible for the digestion of food and the absorption of nutrients. symptoms such as Vomiting and DiarrheaDiarrhea refers to the condition of frequent, watery bowel movements, which can be a sign of infections, digestive disorders, or other health problems. may also occur, caused by stressStress refers to the state of an organism reacting to external stimuli or demands. In veterinary medicine, stress can have physical or psychological effects on animals, impacting their health and well-being. and general weakening of the body.

Since these symptoms can also occur with other diseases, it is important not to consider them in isolation, but in the context of other clinical findings and diagnostic results.

Diagnosis

The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of an insulinoma usually begins with a thorough history and clinical examination of the dog. The veterinarian will assess the dog’s symptoms and order blood tests to measure blood sugar levels. An unusually low blood sugar level may be an indicationIndication refers to a valid reason or rationale for using a specific treatment, medication, or medical procedure. It is based on the diagnosis and the patient's clinical condition. of an insulinoma.

For further clarification, imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or computed tomography (CT)Computed tomography (CT) is an imaging technique that uses X-rays and computer technology to create cross-sectional images of the body. It enables a detailed view of bones, organs, and other structures and is used for the diagnosis of injuries, diseases, and for planning medical interventions. can be used to locate the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation.. These procedures can also help identify metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body. in other areas of the body.

Another important diagnostic test is measuring the insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. concentration in the blood. A high insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. level despite low blood sugar levels is characteristic of an insulinoma. In some cases, a surgical biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. may also be necessary to confirm the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients..

Therapy

Treatment for an insulinoma typically involves a combination of surgical and medical measures. Surgical removal of the tumor is the preferred treatment method if the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is localized and operable. This can alleviate symptoms and significantly improve the dog’s quality of life.

If the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. has metastasized or is inoperable, medical treatments can be used to control insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. production and manage hypoglycemiaHypoglycemia is a condition in which blood sugar levels fall below the normal range. Symptoms may include tremors, sweating, Hunger, confusion, and in severe cases, loss of consciousness.. Medications such as diazoxide or streptozotocin can be used to inhibit insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. secretion and stabilize blood sugar levels.

In addition to medical treatment, it is important to adjust the dog’s diet. A low-carbohydrate, high-protein diet can help keep blood sugar levels stable and prevent hypoglycemic episodes.

Prognosis and follow-up care

The prognosis for dogs with an insulinoma depends on various factors, including the size and location of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions., the presence of metastasesA metastasis is a secondary tumor that originates from a primary, malignant tumor in another part of the body. Metastases indicate that cancer has spread in the body., and the dog’s general health. In general, dogs in whom the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. can be successfully removed have a better prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop..

If the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. cannot be completely removed or has metastasized, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is more guarded. Such cases require close monitoring and possibly lifelong medication to control symptoms and maintain the dog’s quality of life.

Early detection and treatment are crucial for a positive prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop.. Therefore, it is important to consult a veterinarian at the first signs of hypoglycemiaHypoglycemia is a condition in which blood sugar levels fall below the normal range. Symptoms may include tremors, sweating, Hunger, confusion, and in severe cases, loss of consciousness. or other unusual symptoms.

Prevention

Since the exact causes of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. are not fully understood, there are no specific measures to prevent these Tumors. Nevertheless, some general health measures can reduce the risk and support the dog’s general health.

A balanced diet that is rich in proteins and low in refined carbohydrates can help relieve the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation. and reduce the risk of metabolicMetabolic refers to metabolism, i.e. the entirety of chemical processes that take place in a living organism to enable life processes. Metabolic disorders can cause a variety of Diseases in Dogs and cats. diseases. Regular veterinary check-ups can help detect and treat health problems early.

A healthy lifestyle that includes regular exercise and a low-stress environment can also help promote the dog’s general health and well-being. While specific preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. measures for insulinomas are not available, generally supporting the dog’s health can improve its ability to cope with various health issues.

Outlook on current research

Research on insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs focuses on various areas to deepen the understanding of the disease and develop new treatment approaches. One of the key questions is how insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. arise and what genetic or environmental factors promote their development. There is evidence that genetic predispositions may play a role, but the exact mechanisms are not yet fully understood. Researchers are also investigating the molecular and cellular processes that lead to the development of these Tumors in order to identify potential targets for new therapies.

Another important area of research is the improvement of diagnostic procedures. Currently, insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. are usually diagnosed by a combination of clinical examination, blood tests, and imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or CT scans. However, work is being done to develop new biomarkers that could enable earlier and more precise diagnosis. Such biomarkers could help detect the disease at a stage when it is still more treatable.

In terms of the treatment of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs, there are also promising approaches. Surgical interventions are currently the most common treatment method, but they are not always successful, especially if the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. has already metastasized. Therefore, intensive research is being carried out into new drug treatments. Some studies are investigating the use of drugs that can reduce insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. production or inhibit tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. growth. Immunotherapy, in which the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. is used to fight the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions., is also an interesting area of research.

In addition, the role of nutrition in the treatment and management of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. is being explored. There is evidence that special diets with a low sugar and carbohydrate content can help control symptoms and improve the well-being of affected dogs. However, more research is needed to validate these approaches and understand how they can best be integrated into treatment.

Research on insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs is therefore a dynamic field with many exciting developments. There is still much to learn, but the progress made in recent years is promising and could lead to improved diagnostic and treatment options in the near future.

Frequently asked questions (FAQs)

What is an insulinoma? An insulinoma is a rare, usually benignBenign refers to a non-invasive, non-serious condition that is not life-threatening. In medicine, the term is often used to describe benign tumors that do not metastasize, meaning they do not form secondary tumors. tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. that originates in the insulin-producing cells of the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation.. These Tumors lead to excessive production of insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus., which can lead to low blood sugar levels (hypoglycemiaHypoglycemia is a condition in which blood sugar levels fall below the normal range. Symptoms may include tremors, sweating, Hunger, confusion, and in severe cases, loss of consciousness.).

What symptoms do dogs with an insulinoma show? The symptoms of an insulinoma can vary, but often include weakness, tremors, confusion, Convulsions, collapse, and in severe cases, coma. These symptoms result from the low blood sugar level in the body.

How is an insulinoma diagnosed? The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of an insulinoma is usually based on a combination of clinical symptoms, blood tests that show low blood sugar levels and high insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. levels, and imaging techniques such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. or CT scans to locate the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. in the pancreasThe pancreas is an organ that produces digestive enzymes and hormones, including insulin. It plays an important role in digestion and blood sugar regulation..

What treatment options are available for insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs? The main treatment method is surgical removal of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. If surgery is not possible or the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. has already metastasized, drug treatments can be used to control insulininsulin is a hormone produced by the pancreas. It regulates blood sugar levels by promoting the entry of glucose into cells. insulin deficiency or impaired insulin action are key features of diabetes mellitus. production and alleviate symptoms.

Can insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. be cured in dogs? The cure depends on the stage of the disease. If the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. is detected early and completely removed, a cure is possible. In advanced cases where the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. has metastasized, a complete cure is less likely.

What role does nutrition play in the treatment of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment.? An adapted diet can help control the symptoms. Diets with a low content of sugar and simple carbohydrates are often recommended as they can help maintain stable blood sugar levels.

Are insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. more common in certain dog breeds? InsulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. can occur in any dog breed, but some studies suggest that certain breeds such as Boxers and Golden Retrievers may be at higher risk. Further research is needed to confirm these observations.

How common are insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs? InsulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. are relatively rare in dogs compared to other types of Tumors. They usually occur in older dogs and are more common in male than in female animals.

Can insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. be prevented in dogs? Currently, there are no known preventive measures to prevent the development of insulinomasInsulinomas are rare Tumors of the pancreas that produce excessive insulin and can lead to low blood sugar levels. They occur in dogs and cats and require careful diagnosis and treatment. in dogs. However, a healthy diet and regular veterinary check-ups can help maintain a dog’s general health and detect diseases early.

What is the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. for dogs with an insulinoma? The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends heavily on the stage of the disease and the possibility of surgical removal of the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions.. Dogs in whom the tumorA tumor is an abnormal growth of tissue that can be benign or malignant. Tumors can develop in any part of the body and affect various functions. can be removed early often have a better prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop., while the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is more guarded in dogs with metastatic Tumors. However, close monitoring and treatment can help improve the quality of life and prolong survival time.

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

If the condition worsens / symptoms persist, consult a veterinarian.