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Pet Health

What is an oral tumor and types of oral tumors in pets

Oral tumors in pets can encompass a wide range of growths that affect the mouth, gums, tongue, and other oral structures. Some common types of oral tumors in pets include melanoma, squamous cell carcinoma, fibrosarcoma, osteosarcoma, and epulis.

Dr. Gary Hsia

December 17, 2023

Oral tumors in pets can be a source of great concern for pet owners, as they can impact the overall health and well-being of our beloved animals. Understanding the nature of oral tumors, their impact on dogs and cats, and the potential life expectancy of pets with oral tumors is important for providing the best care and support for both pets and their owners.

The term “oral tumor” refers to an abnormal growth of cells in the oral cavity, which includes the lips, inside lining of the cheeks, teeth, gums, tongue, floor of the mouth under the tongue, and the bony roof of the mouth. Oral tumors can be benign or malignant and may originate from various tissues within the oral cavity, such as the mucous membranes, salivary glands, bone, or muscle.

Oral tumors in pets can encompass a wide range of growths that affect the mouth, gums, tongue, and other oral structures. Some common types of oral tumors in pets include melanoma, squamous cell carcinoma, fibrosarcoma, osteosarcoma, and epulis.


A type of cancer that originates from the pigment-producing cells in the skin and mucous membranes. In pets, melanomas can occur in the oral cavity and may present as pigmented masses or ulcers.

Squamous cell carcinoma

A malignant tumor that often arises from the epithelial cells lining the oral cavity. It can be locally invasive and has the potential to metastasize to other parts of the body.


A cancerous tumor derived from fibrous connective tissue. When it occurs in the oral cavity of pets, it can lead to destructive growth and aggressive invasion into surrounding tissues.


A type of bone cancer that can affect the jawbones of pets. It is an aggressive tumor that can cause significant pain and impairment of normal jaw function and may lead to pathologic fractures of the affected bone.


This refers to a benign tumor that arises from the periodontal ligament or gingival tissue. While epulides are generally not metastatic, they can still cause local tissue destruction if left untreated.

What are common signs of oral tumors in dogs or cats?

Some of the typical oral tumor signs in dogs or cats include:

  1. Abnormal growth or mass such as a lump or swelling on the gums, palate, tongue, or other areas within the oral cavity.
  2. Difficulty eating or swallowing, or avoidance of food due to pain caused by the tumor, obstruction of the oral cavity, or discomfort while trying to consume food.
  3. Excessive drooling beyond what is normal for a particular pet can be indicative of oral health issues, including the presence of tumors in the mouth.
  4. Bleeding from the mouth, which may be evident as bloodstains on toys, food bowls, or around the pet’s mouth.
  5. Bad breath, Halitosis, can be a symptom of oral tumors in dogs and cats. The foul odor may persist despite regular dental care.
  6. Pawing at or rubbing the mouth can demonstrate oral pain or discomfort due to oral tumors.

Other signs can include a change in behavior, weight loss, and difficulty breathing; each of which warrants investigation by a veterinarian with difficulty breathing requiring immediate action.

Impact on Pets’ Quality of Life

The presence of oral tumors can significantly impact a pet’s quality of life. In addition to physical symptoms, pets with oral tumors may also exhibit signs of distress or discomfort. They may become less active, withdraw from social interactions, or show signs of depression. Our dogs and cats experience the world differently than we do, living mostly in the moment.

As such, a physical malady can loom large and bring additional uneasiness to our pets. It’s important to monitor closely for any changes in their behavior or physical condition that could indicate a cause for concern such as the presence of oral tumors so prompt action can be taken. If you’re wondering about your pet’s quality of life, take our quality of life scale to get an objective measure of your pet.

Treatment Options

The treatment options for oral tumors in pets depend on various factors including the type of tumor, its stage, location, and the overall health of the pet. The cells of the oral cavity, epithelial cells, are fast growing so early treatment often brings better outcomes. Treatment may involve surgical removal of the tumor, radiation therapy, chemotherapy, or a combination of these modalities.

In cases where surgical removal is feasible, it may offer a chance for long-term control or even cure if the tumor is benign or localized. However, some aggressive or advanced tumors may not be able to be completely excised surgically especially as it can be difficult to remove the tumor with wide margins due to the presence of many important structures without much extra tissue. But even in cases where surgical cure is not possible, the removal of the tumor may result in significant short-term relief.

Radiation therapy can be employed to target residual cancer cells after surgery or as a primary treatment modality for tumors that are not surgically accessible. Chemotherapy may be recommended for certain types of oral tumors to help slow down disease progression or alleviate symptoms.

It’s important to note that while treatment can provide relief and improve the quality of life for pets with oral tumors, it may not always result in the complete eradication of the cancer. The prognosis for pets with oral tumors varies widely depending on individual circumstances.

Life Expectancy In Common Oral Tumor Types

The life expectancy of pets with oral tumors is influenced by multiple factors including the type, stage, size and location of the tumor, age of the individual,response to treatment, presence of metastasis (spread to other organs), overall health status of the pet, and supportive care.

While life expectancy varies widely, the average survival time for dogs with oral melanoma undergoing surgery is less than six months, although when combined with radiation and chemotherapy, can be up to one year. Melanoma immunotherapy also might increase survival time to 18 months or longer. Melanoma is the most common form of oral tumor seen in dogs and the third most common for cats.

The second most common oral tumor in dogs and the most common in cats is squamous cell carcinoma. The survival time for a dog with squamous cell carcinoma after complete surgical excision and radiation therapy is between 10 to 40 months. When chemotherapy alone is used, dogs average between 7 and 8 months (237 days) survival time.

For cats with squamous cell carcinoma, the survival time with surgery alone is less than 3 months unless complete excision is possible in which case surgery is curative.For those with incomplete removal who undergo surgery and radiation average survival times span between 11 and 23 months.

In cases where palliative care becomes necessary due to advanced disease or poor response to treatment, pet owners play a crucial role in ensuring their pets’ comfort and quality of life during their remaining time together. This may involve pain management, nutritional support, environmental modifications to accommodate any physical limitations and emotional support through close companionship.

Seeking Support

Receiving a cancer diagnosis for a beloved pet can be challenging on many levels. While pet parents and veterinary professionals navigate the diagnostic and treatment process together it is important for pet parents to ensure they understand available treatment options, expected outcomes, and supportive care measures.

While families are focusing on the best care for their dog or cat, it is also important to be sure their own needs are taken into account. Connecting with resources such as support groups or counseling services can help families cope with the emotional impact of a pet’s illness.

A Gentle Goodbye At Home

Unfortunately, oral tumors often come with a poor prognosis. Dogs and cats facing a poor quality of life can experience relief from suffering via euthanasia. While each family will approach the question of “when is the right time” differently, the important thing is to have the discussion and explore the options together. When malignant disease can’t be stopped, euthanasia affords families the ability to control when, how, and where they say goodbye. If you are facing euthanasia for your pet, learn more about in-home pet euthanasia or find a CodaPet veterinarian in your city, so you can feel prepared and support your beloved pet as they approach their coda, or tail end, of their journey.

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