고양이 신생물 유발 저혈당 자주 묻는 질문 Q&A — 보호자가 꼭 알아야 할 핵심

Frequently Asked Questions (Q&A) on Hypoglycemia Caused by Tumors in Cats — Key Information Pet Owners Must Know

EndocrineQ&AMeongsiljang Veterinary Advisory Board

Hypoglycemia caused by tumors in cats is rare but dangerous. We’ve compiled the key information pet owners need to know in a Q&A format.

What is hypoglycemia caused by tumors in cats?

A cat blood test sample showing low blood sugar levels

Hypoglycemia induced by feline neoplasms is a condition in which a tumor abnormally lowers blood glucose levels. The most common cause is an insulin-secreting pancreatic tumor (insulinoma), which produces excessive insulin and leads to low blood sugar. Additionally, some tumors can cause hypoglycemia as part of a paraneoplastic syndrome. In cats, hypoglycemia is generally defined as a blood glucose level below 70 mg/dL. Insulinomas may secrete insulin partially or completely autonomously, resulting in alternating periods of normal and low blood glucose. Hypoglycemia can lead to lethargy, weakness, muscle tremors, seizures, and decreased consciousness, and in severe cases, it can cause permanent neurological damage or be life-threatening. Therefore, early detection and prompt intervention are crucial.

What are the main causes of this condition?

The primary cause of this condition is an insulin-secreting tumor, most commonly an insulinoma of the pancreas. Because insulinomas continue to release insulin even when blood sugar levels are low, tissues keep consuming glucose while the liver reduces its glucose production, leading to hypoglycemia. These tumors function partially or completely autonomously, so episodes of low blood sugar may alternate with periods of normal blood sugar. In addition, tumor-induced hypoglycemia unrelated to insulin has been reported in cats. When hypoglycemia affects the nervous system, symptoms such as weakness, behavioral changes, and seizures can occur. These signs often come and go, making them easy for pet owners to overlook. If you suspect your pet is experiencing these symptoms, consult your veterinarian immediately.

Image of pancreatic and hepatic tumors in cats that cause excessive insulin secretion

What are the main symptoms?

The main symptoms of hypoglycemia caused by tumors in cats include weakness, lethargy, fatigue, stumbling or collapsing, muscle tremors, behavioral changes or confusion, loss of appetite, and seizure-like episodes. When blood sugar drops, cats may become anxious or restless, and adrenaline-driven responses such as rapid breathing, vomiting, or diarrhea can also occur. Hypoglycemia due to an insulinoma is often triggered by fasting, exercise, or excitement, and symptoms tend to come and go. If your cat becomes disoriented or slow to respond, seek veterinary care immediately. Hypoglycemia can cause permanent nerve damage or be life-threatening, so do not delay treatment. If these symptoms recur, a definitive diagnosis is essential.

A cat lying on the floor, appearing dazed or disoriented.

Signs requiring immediate veterinary visit

If your pet appears disoriented or experiences seizures, seek veterinary care immediately. Hypoglycemia can be life-threatening, so don’t delay—get emergency treatment right away.

How is it diagnosed?

Diagnosis hinges on measuring blood glucose levels during hypoglycemia while simultaneously checking insulin concentrations. If insulin levels are elevated or remain higher than normal despite hypoglycemia, an insulin-secreting tumor is suspected. In cases where hypoglycemia occurs only intermittently, fasting for up to 72 hours may be used to confirm the condition. The tumor marker chromogranin A may also be detected, and a definitive diagnosis is made by confirming insulin secretion through immunohistochemical examination of the tumor tissue. Abdominal ultrasound or CT scans are used to examine the pancreas and liver to determine the tumor’s location and size, with particular focus on these areas. Based on the results of these combined tests, the veterinarian will develop a treatment plan tailored to the specific characteristics of the tumor.

A veterinarian examining a cat's blood sample under a microscope.

What are the treatment methods?

The cornerstone of treatment is surgical removal of the tumor whenever feasible. Removing the tumor via surgery significantly helps regulate hypoglycemic symptoms. When surgery is not an option or when symptom management is required, glucocorticoids—most commonly prednisolone—are frequently used. This medication alleviates hypoglycemia by inhibiting insulin action and increasing hepatic glucose production. Prednisolone should be administered at the lowest effective dose capable of preventing hypoglycemia. While frequent, small meals are recommended, an ideal diet has not yet been clearly defined. Your veterinarian will develop a treatment plan tailored to your pet’s weight and condition, and regular blood glucose monitoring along with periodic examinations are necessary to evaluate treatment efficacy.

A veterinary team performing tumor removal surgery on a cat

How can it be managed at home?

To help prevent hypoglycemia, it’s better to offer small, frequent meals rather than large portions at once. However, since the ideal diet has not yet been clearly established, it’s best to work with your veterinarian to determine the most appropriate feeding plan. Keep in mind that fasting, exercise, and excitement can trigger low blood sugar, so carefully manage the timing between activity and meals. Regularly monitoring your cat’s blood glucose at home using a feline-calibrated glucometer and keeping a record of the readings can be very helpful. If you suspect hypoglycemia, administer glucose or food while your cat is still conscious; if symptoms are severe or consciousness is impaired, seek immediate veterinary care. Stay in close communication with your veterinarian to collaboratively adjust the treatment plan as needed.

A cat eating small amounts of food several times a day

Comparison of characteristics by hypoglycemia type

Item	Cause	Main symptoms	Treatment method	Prognosis
Neoplasia-induced hypoglycemia	Pancreatic insulin-secreting tumor (insulinoma)	Weakness, decreased consciousness, seizures, lethargy	Surgical removal, glucocorticoids (prednisolone)	Symptom control/improvement possible with tumor removal
Insulin overdose	Excessive insulin injection	Drowsiness, tremors, shock	Glucose supplementation, insulin dose adjustment	Can be normalized
Decreased liver function	Decreased glucose production due to liver damage	Loss of appetite, weakness, shock	Liver-protective treatment, nutritional support	Varies depending on the condition

Since each type has different causes and treatments, an accurate diagnosis is essential.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Could a sudden collapse in a cat be caused by hypoglycemia induced by a tumor?

If your pet suddenly collapses or experiences seizures, it could be a sign of hypoglycemia. You should seek veterinary care immediately. The veterinarian will perform blood tests to check both blood glucose and insulin levels.

Is this condition treatable?

Surgical removal of the tumor can help control hypoglycemia. If surgery is not feasible, symptoms can be managed with medications such as glucocorticoids (prednisolone) or by feeding more frequent, smaller meals.

Is prevention possible?

Early detection through regular health check-ups is the most important thing. In particular, as pets get older, we recommend regular check-ups.

Can symptoms improve with dietary management alone?

Feeding small, frequent meals can help alleviate hypoglycemia, but the definitive treatment is tumor removal. Dietary management serves as an adjunctive therapy.

Is this condition common in cats?

This condition is generally rare. However, extra caution is warranted in cats with insulin-secreting pancreatic tumors (insulinomas). Early detection is key.

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References

[1] Nelson, R.W., et al. (2021). Small Animal Critical Care Medicine, 3rd Edition. Elsevier Saunders.

[2] Feline Emergency and Critical Care Medicine, 2nd Edition (2020). Elsevier.

[3] Plumb's Veterinary Drug Handbook, 9th Edition (2022). Wiley-Blackwell.