Oral tumors in dogs: What every pet owner needs to know

Konina zgodba

Gennaio 24, 2024

AHP Team Attends Veterinary Oncology Congress in the Netherlands

Febbraio 14, 2025

What are oral tumors?

Oral tumors in dogs are abnormal growths that can appear in various parts of the mouth, including the gums, tongue, and roof of the mouth. These tumors can be benign (non-cancerous) or malignant (cancerous). Although benign tumors do not spread, they can still behave locally agressively. Malignant tumors, despite being locally aggressive, have also a potential to metastasize to regional lymph nodes and other parts of the body.

With early detection and proper treatment, the prognosis for most oral tumors in dogs is typically very good. Prompt consultation at the first sign of any changes in your dog's mouth is crucial to ensure the best possible outcome.

Common types of oral tumors in dogs

Squamous cell carcinoma:
- Description: Typically found on the jaws, this tumor can also affect the mouth lining, tongue, and tonsils. It invades surrounding tissues, including bone, and can metastasize, although this usually occurs later in the disease.
- Treatment and prognosis: Surgery and radiotherapy are the primary treatment options. Early detection and aggressive treatment are essential for a good prognosis.
Malignant melanoma:
- Description: This common oral tumor in dogs can vary greatly in appearance, making it challenging to diagnose sometimes.
- Prognosis: Unfortunately, the prognosis is poorer in comparison with squamous cell carcinoma due to the tumor’s tendency to spread early and frequently to regional lymph nodes and most frequently lungs.
- Diagnosis and treatment: Early diagnosis is crucial. Smaller tumors (under 2 cm) with no metastasis have a better prognosis, especially with aggressive treatment such as surgical removal and/or radiotherapy for loco-regional control, and immune therapy.
Fibrosarcoma and osteosarcoma:
- Description: These tumors are locally very invasive, making them more challenging and difficult to treat.
- Treatment: A combination of surgery and radiotherapy is often used to optimise treatment outcomes.
Canine acanthomatous ameloblastoma (CAA) and peripheral odontogenic fibroma (POF)
- Description: These are the most frequently diagnosed benign tumors and often present as proliferative gingival growths that also invade the underlying bone.
- Prognosis and treatment: Surgical resection carries an excellent prognosis. Both tumor types are radiosensitive, so radiotherapy can also be used effectively for treatment.

Squamous cell carcinoma affecting the rostral mandible before and after surgery.

Oral malignant melanoma before and after radiotherapy treatment.

A 10-year-old Cane Corso with a right maxillary mass, present for nearly 8 months, has been diagnosed with T-cell lymphoma. T-cell lymphoma is known to respond well to radiotherapy, which can quickly shrink the tumor and alleviate pain, thereby significantly enhancing the patient's quality of life.

Early detection of oral tumors can significantly improve treatment outcomes and improve the quality of life of patients.

Here are some signs to be aware of:

Bad breath (halitosis)
Excessive drooling
Difficulty eating or reluctance to eat
Bleeding from the mouth
Swelling or masses in the mouth
Loose teeth or loss of teeth
Weight loss

If you notice any of these symptoms, it’s crucial to schedule an appointment promptly.

An oral malignant melanoma (gingival) affecting the lower jaw before and after radiotherapy treatment, showing the complete disappearance of the tumor. Additionally, a second picture is showing a CT scan of a dog with squamous cell carcinoma treated with total mandibulectomy, resulting in an acceptable functional and cosmetic outcome.

Tonsillar squamous cell carcinoma treated with radiotherapy shows a complete response.

Diagnosing oral tumors

Diagnosis usually involves a thorough oral examination followed by diagnostic tests such as:

Biopsy: Taking a small tissue sample from the tumor for histopathological and imunohistochemical examination.
CT scanning, radiography: Imaging techniques to determine the loco-regional extension of the tumor and if it has spread to other distant organs.
Blood tests: To check overall health and organ function.

Treatment options

Treatment depends on the type, size, and location of the tumor, as well as whether it has spread. Common treatment methods include:

Surgery: The primary treatment for many oral tumors, especially if they are localized and accessible.
Radiation therapy: Used as a single treatment method or as a part of multimodal treatment approach, often together with surgery, particularly for tumors that are difficult to remove completely.
Chemotherapy: May be recommended as a part of multimodal approach for certain types of malignant tumors such as lymphoma or mast cell tumors for instance.
Palliative care: For advanced cases, focusing on quality of life and symptom management.

Preventive measures

While it’s not always possible to prevent oral tumors, regular follow-ups and good oral hygiene can help in early detection and treatment.

Schedule annual dental exams for your dog.
Brush your dog’s teeth regularly.
Provide a balanced diet and appropriate chew toys to help maintain oral health.
Monitor your dog's mouth for any changes or unusual growths.

Oral tumors in dogs can be a serious health concern, but with early detection and appropriate treatment, many dogs can recover and enjoy a good quality of life. At Animal Hospital Postojna, we are dedicated to providing comprehensive care for your pets. If you have any concerns about your dog's oral health, don’t hesitate to contact us for an appointment.

dr. Ana Rejec Jenček, DVM, PhD, Dipl EVDC