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Pet Health

Are Lumps and Bumps Always Cancer? Understanding Non-Cancerous Masses and Tumors in Pets

Not all masses and tumors in pets are cancerous. Understanding non-cancerous masses and tumors in pets is important for pet owners to provide the best care and support for their beloved companions.

Dr. Gary Hsia

December 08, 2023

Pets are cherished members of our families, and their health and well-being are of utmost importance to us. When we hear the word “tumor” or “mass,” it can evoke fear and concern for our four-legged family members. However, not all masses and tumors in pets are cancerous. Understanding non-cancerous masses and tumors in pets is important for pet owners to provide the best care and support for their beloved companions.

What Are Non-Cancerous Masses and Tumors?

Non-cancerous masses and tumors, also known as benign growths, are lumps or growths that can develop in various parts of a pet’s body. They are abnormal but often non-threatening in and of themselves. These growths are composed of cells that do not invade nearby tissues or spread to other parts of the body, unlike malignant cancerous tumors. While they may not be malignant, non-cancerous masses can still cause discomfort or health issues for pets, depending on their size, location, and impact on surrounding tissues.

Types of Non-Cancerous Masses and Tumors

There are several types of non-cancerous masses that can affect pets. Some common examples include lipomas, which are soft, fatty lumps that often occur under the skin; sebaceous cysts, which are filled with a cheesy or oily material; fibroadenomas, typically found in the mammary glands of intact female pets; and histiocytomas, which are benign skin tumors commonly seen in young pets. Each type of non-cancerous growth may present differently and require specific diagnostic approaches and treatment considerations. Your trusted family veterinarian can provide guidance and care tailored to your pet’s needs.

Common Non-Cancerous Tumor Signs in Pets

Non-cancerous tumors, or benign tumors, can occur in pets and may exhibit various signs and symptoms relating to their type, size, and location on your pet. It’s important for pet owners to be aware of these signs to ensure early detection and appropriate medical attention. Some common non-cancerous tumor signs in pets include:

Lumps or Bumps

One of the most noticeable signs of a non-cancerous tumor in pets is the presence of lumps or bumps under the skin. These growths may vary in size and can be felt during petting or grooming.

Changes in Behavior

Pets with non-cancerous tumors may exhibit changes in behavior such as increased irritability, restlessness, or reluctance to engage in physical activities due to discomfort caused by the tumor. Another common sign is changes in grooming habits which may include licking, scratching, or chewing excessively at certain areas.


Non-cancerous tumors can cause localized swelling in specific areas of the body. This swelling may be accompanied by tenderness or pain upon touch.

Changes in Appetite

Some pets with non-cancerous tumors may experience changes in appetite, either a decrease or increase in food consumption, which could be indicative of discomfort or pain associated with the tumor.

Limping or Lameness

Tumors located near joints or bones can lead to limping or lameness in affected pets. This sign is particularly relevant when the tumor is pressing on nerves or causing musculoskeletal pressure and discomfort.

Skin Changes

Non-cancerous tumors can cause changes in the skin overlying the affected area, such as redness, changes in pigmentation, ulceration, or hair loss.


In certain cases, non-cancerous tumors may produce discharge from the affected area, which could be pus-like or bloody.

It’s important to note that these signs are not exclusive to non-cancerous tumors and can also be indicative of other health issues, which may include cancerous tumors. Therefore, it is crucial for pet owners to seek veterinary advice for proper diagnosis and treatment if any of these signs are observed in their pets.

Management of Non-Cancerous Masses and Tumors in Pets

Non-cancerous masses may require management depending on their size, location, and potential impact on the pet’s health. Your veterinarian may be able to diagnose some benign tumors on visual exam and palpation (gently feeling) alone. However, most masses are not so easily or accurately differentiated and will require further diagnostics such as microscopic examination of the cells (cytology) or of the tissue (biopsy). The management of non-cancerous tumors in pets typically involves monitoring, surgical removal, or other treatment options based on the specific characteristics of the mass.

Surgical removal is a commonly recommended treatment for non-cancerous masses. This is especially true if the mass is causing discomfort, interfering with the pet’s movement, or impacting its overall well-being. Surgical removal is often beneficial when masses are easily accessible, when the procedure poses minimal risk, and when removal would improve quality of life.

For non-cancerous masses that are small and not causing any immediate health concerns, a veterinarian may recommend a strategy of closely monitoring the mass over time. This involves regular check-ups and tumor mapping to assess any changes in size, shape, or consistency of the mass as well as any changes to the pet’s comfort and bodily functions. Monitoring is crucial to ensure timely intervention if the mass becomes problematic or requires intervention in the future.

In some cases, non-cancerous masses may be managed using alternative treatment options such as cryosurgery (freezing the mass), laser therapy, radiation therapy, immunotherapy, or hormonal therapy. These treatments are considered when surgical removal is not feasible or poses a high risk to the pet’s health.

Prognosis for Pets with Non-Cancerous Masses or Tumors

The prognosis for a pet with a non-cancerous mass or tumor is generally positive, especially if the mass is diagnosed early and appropriate management steps are taken. Surgical removal of benign tumors often leads to a complete recovery with minimal risk of recurrence.

However, it’s important to note that each case is unique, and prognosis can vary based on factors such as the location of the mass, its size, and any potential complications associated with its management. It is also important to understand that the occurrence of a new growth may occur in a different location and be unrelated to the original tumor. Each new lump and bump should be assessed by a veterinarian.

Management Tips for Non-Cancerous Masses and Tumors

Post Op Recovery Care

For at-home care of pets with non-cancerous masses or tumors, it’s essential to follow any post-operative care instructions provided by the veterinarian after surgical removal. This may include keeping the incision site clean and dry, administering prescribed medications, and monitoring for any signs of infection or complications.

Additionally, providing a comfortable and stress-free environment for the pet during recovery is helpful for optimizing recuperation. This can involve creating a quiet space for rest and minimizing physical activity as advised by the veterinarian. You may wish to limit access to or isolate your pet from other more rambunctious family members. Be sure the pet always has access to fresh water, nutritious food, and has an appropriate place for potty breaks.

Quality of Life

In cases where a non-cancerous mass cannot be surgically removed and continues to grow, quality of life can become an important consideration. Although not usually invasive to local tissues, a tumor that grows continually can exert significant pressure on the underlying tissue.

Depending on the location this can manifest as difficulty swallowing, breathing, urinating, defecating, or any number of other bodily functions. In such situations, veterinary care is required and the topic of end-of-life care should be explored.

One form of end-of-life care is palliative care, which focuses on managing pain and maintaining the quality of life that remains. This can involve working closely with a veterinarian to develop pain and symptom management plans tailored to the individual needs of the pet.

These plans can be reassessed and adjusted over time as the pet’s needs change. Please note that palliative care is not always an option, especially for pets suffering from respiratory distress; if your pet is having difficulty breathing seek veterinary care immediately.

A Gentle Goodbye At Home

When palliative care is not an option and your pet's quality of life is in decline the kindest next step may be euthanasia. Take some time to learn about your options and discuss them with your family. Euthanasia is the gift of ending a deteriorating painful quality of life and can be provided in the privacy of your home. Learn more about in-home pet euthanasia or find a veterinarian specializing in pet euthanasia and end-of-life care near you, so you can understand all of your options.

Dr. Gary Hsia

Fresno, CA


Dr. Gary graduated from the University of Illinois College of Veterinary Medicine in 2010. After graduation, he moved west. Dr. Gary spent a year at a mixed animal practice in Oregon before moving to Fresno where he worked at All Creatures Veterinary Clinic from 2011-2021.  Read More

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