고양이 뇌하수체 종양 자주 묻는 질문 Q&A — 보호자가 꼭 알아야 할 핵심

What Are Pituitary Tumors in Cats? — Signs of Hormonal Imbalance and Diagnostic Points

EndocrineQ&AMeongsiljang Veterinary Advisory Board

Pituitary tumors in cats are a common endocrine disorder that can cause hormonal imbalances, making early detection and management crucial. Here’s a summary of the key information every pet owner should know.

What Are Pituitary Tumors in Cats?

Medical illustration showing the location of a pituitary tumor in a cat

Pituitary tumors in cats develop in the pituitary gland, which is located at the base of the brain. The most common type is an adenoma, a benign tumor of the anterior pituitary. These tumors can affect the entire body by overproducing hormones such as growth hormone (GH) or adrenocorticotropic hormone (ACTH). Excess growth hormone can lead to acromegaly, while excess ACTH stimulates the adrenal glands, potentially causing hyperadrenocorticism (Cushing’s disease). Although most of these tumors are benign adenomas, they can cause neurological signs if they grow large enough to compress the brain. Symptoms may include vision loss, balance problems, and seizures. Early detection is crucial. If you notice any of these signs, please consult your veterinarian promptly. With appropriate treatment, your cat’s quality of life can be significantly improved.

Why Do Pituitary Tumors Develop in Cats?

The exact cause of pituitary tumors remains unknown. However, clinical observations suggest they tend to develop gradually in middle-aged to senior cats, so older cats require closer monitoring. When a tumor secretes excessive hormones, it can disrupt the pituitary gland’s normal hormonal regulation. For instance, cats with hyperadrenocorticism caused by excessive ACTH production are known to concurrently have diabetes in most cases (approximately 77–80%). This can lead to systemic symptoms such as increased thirst, increased urination, and weight changes. While it is difficult to pinpoint specific causes for prevention, regular health check-ups are crucial for early detection, especially in senior cats.

An image symbolizing the risk factors for pituitary tumors in senior cats

What Are the Main Symptoms?

The main symptoms of pituitary tumors in cats are as follows. If you notice any of these signs, please consult your veterinarian.

Excessive thirst and urination: Drinking water frequently and urinating often.

Increased appetite: A sudden increase in food intake.

Weight loss: Losing weight despite eating more than usual.

Fatigue and lethargy: Sleeping most of the day or showing reduced activity.

Vision impairment or ocular abnormalities: Blurred vision or abnormal eye movements.

Visualizing excessive thirst in cats caused by pituitary tumors

Signs Requiring Immediate Veterinary Visit

If your cat suddenly faints, has seizures, or experiences a rapid decline in vision, you should go to the vet immediately. This could be a serious complication caused by increased intracranial pressure.

How Is It Diagnosed?

Diagnosing a pituitary tumor in cats requires a combination of tests. First, endocrine function tests, such as blood work, are used to determine whether the tumor is functional—meaning it secretes excessive hormones—or if it is associated with pituitary insufficiency. However, blood and imaging tests alone cannot definitively confirm whether the tissue is actually overproducing hormones, so veterinarians make a diagnosis by integrating results from multiple tests. CT (computed tomography) or MRI (magnetic resonance imaging) scans are used to identify the tumor itself. These imaging studies reveal the tumor’s size and location, as well as whether it has invaded surrounding brain tissue. Your veterinarian will recommend the most appropriate tests for your cat’s condition, and early detection helps in developing an effective treatment plan.

MRI images of a pituitary tumor in a cat

What Are the Treatment Options?

The treatment approach depends on the tumor’s size, location, and whether it is secreting hormones. Medications can be used to control hormone excess. Surgical removal of the tumor is an option, but because the pituitary gland is located deep within the skull, surgery can be challenging. Radiation therapy is effective in suppressing tumor growth. Your veterinarian will develop the optimal treatment plan by considering your pet’s condition and your family’s circumstances. Regular follow-up examinations are necessary even after treatment.

Radiation therapy scenarios for feline pituitary tumors

Comparison Table of Treatment Methods

Item	Efficacy	Side effects	Cost
Medication	Moderate efficacy	Fatigue, vomiting, decreased appetite	Inexpensive
Surgical treatment	High cure rate	Risk of infection, bleeding	Very high
Radiation therapy	Good efficacy	Skin reactions, fatigue	Moderate

The treatment method depends on the cat's overall health condition and tumor size.

Points to Note During Treatment

During medication, carefully monitor your cat’s appetite, bowel movements, and behavior. If you notice any sudden changes, contact your veterinarian immediately. Overdosing can cause side effects.

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

Can pituitary tumors in cats be treated?

Yes, in many cases, hormone excess can be controlled and symptoms alleviated through medication or radiation therapy. Depending on the tumor’s size and location, surgery (hypophysectomy) may also be an option. Early detection and consistent management are key.

Does a large tumor mean surgery isn't an option?

Whether surgery is possible depends on the tumor’s size and location. Surgery may be difficult if the tumor is very large or invasive, or if there are concurrent conditions that increase anesthesia risk. The veterinarian will make the decision based on MRI and CT results, and in such cases, radiation therapy can be an alternative.

How long can a cat live after being diagnosed with a tumor?

It is well known that survival time cannot be predicted solely by tumor size or type. One study found little clear correlation between tumor size, tumor type, neurological symptoms, and survival time. Targeted therapies such as radiation can help manage diabetes and improve neurological symptoms. Since survival time can vary significantly depending on the individual’s condition, please consult with your veterinarian.

Can it be prevented?

Since the exact cause remains unknown, there’s no definitive way to prevent it. For older cats, early detection through regular health check-ups is especially important.

My cat has lost its appetite while on medication. What should I do?

Loss of appetite can be a side effect of medication. Do not adjust the dosage on your own; instead, consult your veterinarian about adjusting the medication or exploring supportive measures. Offering small amounts of treats may also help stimulate your pet’s interest in eating.

7 Key Points for Canine Thyroid T4 Testing by Veterinarians — From Timing to Result Interpretation

7 Key Tips from Veterinarians for Managing Thyroid Nodules and Cysts in Dogs

7 Key Symptoms and Management Essentials for Canine Thyroid Cancer, Explained by Veterinarians

Post-Surgical Activity Restriction Guide: Management by Recovery Stage

Pet Blood Pressure Measurement and Normal Values

Is Your Dog Experiencing Her First Heat? — Signs of Estrus and When to Visit the Vet

When Is a Cesarean Section Necessary for Puppies? — Key Indications and Recovery Essentials

When Are Newborn Puppies and Kittens in an Emergency? — A Guide to Critical Warning Signs You Must Not Miss

Frequent Vomiting and Soft Stools? — Key Points for Choosing Sensitive Stomach Dog Food

How Do Weight-Loss Prescription Diets Differ from Regular Diets? Ingredient Differences and Selection Criteria

References

[1] Warman, S. (2023) 100 Top Consultations in Small Animal General Practice. Elsevier.

[2] Braun, U. et al. (2022) Fundamentals of Veterinary Clinical Pathology, 3rd Edition. Wiley-Blackwell.

[3] BSAVA (2021) Manual of Canine and Feline Dermatology, 4th Edition. BSAVA Publications.